Andrea talks Cavitation: The Sound of You Ignoring Expensive Problems

Andrea shows up soaked, slightly unhinged, and absolutely done with your circulation system’s bullsh*t. 

We’re talking pools so flooded they look like they’re trying to return to the ocean, equipment gasping for air, and homeowners acting like water movement is optional.

🫀 The Heart of the Pool (And Yours Is Probably Failing)

You’ve got:

•  filtration (kidneys) 
•  chemicals (liver) 

…but today?

👉 We’re talking about the heart

And if your circulation sucks…

your whole pool is basically a stagnant, lukewarm petri dish with commitment issues.

🌊 Circulation: The Thing Nobody Talks About (Because It’s Not Sexy… Until It Breaks)

Andrea breaks it down:

👉 Pumps move water
 👉 Water movement = EVERYTHING
 👉 No movement = congrats, you own a decorative swamp

You can dump all the chlorine you want in there…

If it’s not moving?

👉 It’s just sitting there like a drunk guy at a bar doing absolutely nothing useful.

🧠 Why Your Pool Keeps Looking Like Trash

Dead spots.

You know… those little areas where:

•  debris hangs out 
•  algae sets up a summer home 
•  and your dignity goes to die 

If you keep seeing the same pile of crap every week?

👉 That’s not coincidence
 👉 That’s your circulation system flipping you off

🤢 Let’s Talk About What’s Actually in Your Water

Surface water = the nastiest part of the pool

Andrea said it. Not me.

That’s where:

•  body oils 
•  sunscreen 
•  spit (yeah… spit) 
•  and whatever that kid just sneezed 

all hang out together like a disgusting little party.

And you’re swimming in it like:
 👉 “Ahh, refreshing.”

No.
 No it’s not.

⚠️ Then It Gets Dark… Like REAL Dark

We go from “dirty water” to:

👉 suction entrapment
 👉 hair getting wrapped up like a horror movie
 👉 limbs getting stuck
 👉 and yeah… evisceration

This episode goes from pool tech to:
 👉 “why this industry should come with therapy”

REAL fast.

🧰 Meanwhile, On Your Equipment Pad…

Your pump is over there:

👉 screaming
 👉 cavitating
 👉 sounding like it swallowed a bag of gravel

And you’re ignoring it like:

“Eh… it’s probably fine.”

It’s not fine.

That’s your pump begging for help before it dies a violent, expensive death.

🧪 The Math You Hate But Need

Turnover rates, flow rates, formulas…

Andrea hits you with the reality:

👉 One turnover doesn’t clean sh*t
 👉 You need multiple passes
 👉 This is a PROCESS, not a one-night stand

🤬 Pool Owner Reality Check

You don’t:

•  clean your baskets 
•  check your flow 
•  fix broken drain covers 

…but you DO:

👉 complain about cloudy water
 👉 question your pool tech
 👉 and act shocked when things go sideways

Pick a struggle.

💀 Final Thought

This episode is a wake-up call.

Your pool is not:
 👉 self-cleaning
 👉 self-circulating
 👉 or magically maintained by vibes

It’s a system.

And if the heart isn’t pumping?

👉 Everything else is just slowly dying.

Transcript

SPEAKER_01 0:53

Hello. Welcome to the Talking Pools podcast. It's Tuesday and I am Andrea Unfiltered. So thanks for joining me. Thanks for listening. How was y'all's week? I got rained on so hard today. I had pools that were overflowing. Had one pool in a screen enclosure that was the pool was underwater. That's all I can say. If you don't know, if you can't picture that, I mean just pictured a flooded bull. So that's gonna be fun next week when I go to check the chemicals. Alright, well, so if you have been listening these last couple of weeks, again, thank you, you know that I have been talking about the three main components of a beautiful, healthy swimming pool. We talked about filtration, which is the the kidneys of the pool. I don't know why I keep forgetting my own analogy because I keep I'm just confusing myself and also it feels like it's been months and months since I've been talking about this. Kidneys of the pool. We talked about the chemicals, which is the liver of the pool. And now I'm gonna talk about what brought this whole thing up in the first place, what caused me to make the whole body analogy, I guess. I'm gonna talk about the actual heart, not the filter, the heart of the pool.

SPEAKER_02 3:18

Pool magazine is the app for keeping your fingers on the pulse of the pool industry. You'll find featured news, editorials, podcasts, videos, and more on the Pool Magazine app. Download on Google Play and the App Store.

SPEAKER_00 3:47

In an industry built not just on skill but on those willing to teach it, there's a call to recognize the people behind the professionals. The Talking Pools Podcast is now accepting nominations for its 2026 Mentor of the Year Award, honoring those who don't just have the answers, but teach others how to find them. If someone helped shape your path in this industry, now is the time to return the favor. Visit cpoclass.com. Click on the Talking Pools Podcast Mentor Award tab, and submit your mentor's name up until May 15th, 2026, because behind every great pool professional, there's someone who showed them how to think.

SPEAKER_01 4:28

And now I'm gonna talk about what brought this whole thing up in the first place, what caused me to make the whole body analogy, I guess. I'm gonna talk about the actual heart, not the filter, the heart of the pool, which is the circulation system, right? Because the heart moves the water or the blood. The blood the heart moves the blood, right? We're comparing it to a body, so the pool water is like our life-giving blood. Life-containing. I don't know. There's a lot of things that go into life. I don't have time for that in this podcast. Oh my goodness. Starting off kind of weird here. All right. Circulation, right? Rarely do I hear anybody talking about the actual circulation and the water movement and everything that goes into it. So here we are. Let's get into it. Let's jump in. Let's dive in, shall we? Pool water circulation. The word circulation refers to how water moves within the pool. And this is shaped by various influences, including the shape of the pool itself and controlled by hydraulic principles. This is part of the reason why we say every pool is different, is because every single circulation system is going to be different. Factors affecting circulation include the inlet placement and design. Um, I'm just gonna go ahead and clarify and say that that means the suction and the returns, suction outlets, return inlets. Always get those backwards. And then I gotta double check myself. I'm not going to. If I got it wrong, I'm sorry. You know what you know what I meant. So you have the placement and design of the returns and the suction points. You have the circulation pumps themselves, one or more. You have the pool shape and contour. You have the piping and the fittings. Lots of other things can affect that as well. So anything obviously in the pool. The placement of the heaters and skimmers in the main drain have a minor effect on circulation. Some pools don't even have main drains. Some pools don't have skimmers. Some pools don't have heaters. An appropriately designed circulation system ensures there is efficient removal of surface water. So we need consistent and uniform dilution of treated and filtered water returning to the pool to maintain optimal water quality. The primary component of the circulation system is the pump, which ensures the movement of water throughout the piping network. The heart. This functions, I'm sorry, functions essential to water quality, such as filtration, chemical treatment, and temperature regulation are ineffective without continuous water flow. So if the water is not moving, none of that's gonna happen, right? So we have two types of circulation systems. They can be a direct suction, so you have your skimmers. Direct suction means that the pump is drawing water directly from the suction outlets. In an overflow system, the displaced water is collected in a gutter or a skimmer or in a collection tank. And the collection tanks are usually open to the atmosphere, and then the um they're moved to the pump through gravity, usually in commercial pools, or the suction of the pump draws the water to it. And now we have the turnover rate. This refers to how long it takes for the pool's circulation system to filter a volume of water equal to the entire pool through the filter. Filter through the filter. I wrote that weird. Within the pool, filtered water becomes mixed with unfiltered water, resulting in partial dilution of contaminants. Pollutants are gradually removed through ongoing dilution, and this process must be conducted repeatedly to meet established water quality standards. I was kind of thinking like the clean water gets dirty when it goes back into the pool, which is unfiltered, but you're the clean water is diluting the dirty water. So the more times the water is turned over, the less dirty it is. According to the mathematical model, a single turnover results in filtration of 63% of the water, leaving 37% of it unfiltered. And then with each subsequent turnover, the percentage of water that is unfiltered decreases. So after the second turnover, it's reduced to 14%. The third turnover, it drops to uh 5%. And then after four turnovers, percent of the water is unfiltered. And this is the as this is most standards, most codes in commercial pools. The standard turnover rate is six hours. The required turnover rate specification establishes the essential minimum flow rate for all pool operations. The turnover rates listed below represent industry standards recognized by most regulatory authorities. So for pools it's six hours. For spas it's 30 minutes, waiting pools is one to two hours, water parks is one to four hours, and hospital and health club pools are as low as three hours. For me, I like my residential pools to run for eight hours. I guess six hours is fine. You know, obviously they're not the same as commercial pools, but so for the flow rate, you need a flow meter, and this bad boy is installed on the return line after all the equipment just before the water re-enters the pool. To meet the necessary turnover rate, there must be an adequate flow rate. The connection between flow rate and turnover rate is as follows. There's another math formula for you. The flow rate equals the pool volume divided by the turnover rate divided by 60 minutes. So for the turnover rate, it's the pool volume divided by the flow rate divided by 60 minutes. The flow rate is the pool volume divided by the turnover rate. Excuse me, the pool volume divided by the turnover rate divided by 60 minutes. The water flow slows down when obstructed. So cleaning the filters and clearing skimmers or pump baskets or any kind of cleaner or whatever basket, any kind of basket typically restores the proper flow. Also make sure you check the impeller if you have to pull lots of hair out of the pump basket. That is one of my least favorites. I'm not real sure if hair or band-aids is more favorite, more is more preferred. I'm being sarcastic. I don't prefer either of them. I feel like band-aids are more gross than hair. Let me know what you think. Does hair make you gag or do band-aids make you throw up? Which one is it? Alright, so we have the suction side elements and entrapment. And I just want to start off by saying that I saw some I saw someone on Facebook asking the question, what is the VGBA safety act? And I was more offended by the answers this person got than by the person actually asking the question. Because some people were like, oh, you should know what this is. And as soon as I started reading some of the answers, because that was my first reaction too, like, wow, really, you don't know what this is, like in your pool company. But then like I realized, yo, they were not asking that because they needed the info. They were asking that because clearly a lot of other people need the info. So that's what I wanted to kind of preface this next section with is that everything I'm about to talk about in this little section here, all of it is covered under the VGBA Safety Act, the V Virginia Graham Baker Safety Act. And she was the daughter or granddaughter of a senator, and she was a victim of drowning. And so they were able to change a lot of the code and the regulations. And so all of these things like all of these things are covered under this safety act. It is not just about dual main drains, which is what everybody kept saying. Everyone kept saying, Oh, it's dual main drains. You have to have dual main drains. It's not just about the drains, it's not just about drain covers, it's all of this. Ready? Let's go. So we all know that the pumps vacuum flow can trap people and trap people, putting them at risk of injury or drowning in the pool. And there are five types of entrapment. The first one is hair. And I told a guy about this today, and I could tell that's one of the things that not a lot of people think about, especially men with short hair. They don't think about people with long hair. Your hair will get pulled into the suction outlet and then can become tangled around the drain covers and get all knotted up and tangled. And then even if you do shut the pump off, it's gonna make it hard to get your head up out of the water if it's all tangled up in the drain covers. This is why it's a good idea to always braid your long hair, tie it up. It's fun to play mermaids, I know, but it's much safer to have your hair tied up. It's also better for your hair anyway. Less tangles, less nostalgs, less breakage, etc., etc. etc. So you have limb entrapment, which is your arms or legs becoming stuck or sucked into the outlets. Okay, moving on. Body entrapment is when your torso becomes stuck to a suction outlet. This isn't funny. Evisceration or disembowelment is caused by the force of the pump suction. That is when you land on the drain cover in the right way, where your intestinal organs are the pump removes them. Then you have mechanical entrapment, which is jewelry or bathing suit, strings or beads or you know, fringes, tassels, things like that. Um, I said jewelry, that's mechanical entrapment. A system may be engineered and maintained to minimize or prevent the risk of direct suction entrapment and associated individual and associated injuries to individuals, excuse me. To avoid entrapment or hair becoming tangled, always ensure drain covers are secured over all suction outlets. These covers should only be removable with a tool. They should not just pop off, come off. The anti-entrapment covers are intended to stop the torso and arms from obstructing the cover, and they also help prevent hair from getting tangled around it. The risk of entrapment can be significantly reduced through the installation of dual main drains equipped with anti-entrapment covers. Proper spacing between the drains ensures that an individual cannot obstruct both simultaneously. Eliminating direct suction is the most reliable method for mitigating entrapment risk. Certain systems achieve this by removing direct suction outlets from the pool or spa and employing a gutter system or surge tank, which is a gravity system, and in such configurations, water exits the pool and is directed into a collection pit or balance tank where it is subsequently drawn by the pump suction and recirculated back into the pool. Incorporating atmospheric vents into circulation systems can lower the likelihood of evisceration or body and limb entrapment. However, there is currently no evidence that vent lines prevent hair from becoming entrapped. I wish this fly would get entrapped, dang it. There are devices known as safety vacuum release systems. These are part of the circulation system and help prevent entrapment. They may offer extra protection against body or limb entrapment, but there is no proof that SVRS systems stop hair entrapment or evisceration. So these devices measure the vacuum pressure on the pump, and then when it becomes blocked, when that increases, it shuts the pump off. Main drains. The main drain is typically found in the deepest area of the pool. Although, as I mentioned, some builders do not include these in the pool. I don't think I've ever had one where the builder purposefully did not build, did not include a main drain, but you know, I'm sure we've all had a pool where the drain was leaking and so they just plugged it. I got a bunch of those. In commercial swimming pools, main drain covers must be checked daily. This is during vacuuming, but I mean you still should check it even if you're not going to vacuum, make sure nothing's broken. I actually have a residential pool where they have a really old drain cover. It's like way outdated, totally not VGB compliant. And I let them know about it in this app, but I actually got my net caught on it. And I told and I immediately told the homeowner, I was like, tell these kids, because they're older kids, they're teenagers, I was like, tell them to stay the hell away from this drain cover if you're not gonna fix it. And I was like, you really need to replace it. You can turn the pool off so that they so that there's no risk of suction entrapment from the pump, but you they could still get their clothes stuck on the broken part of the plastic. Um so yeah, if any part is cracked or broken, and now this is for commercial pools, the pool should be closed immediately until the cover is replaced because this says defects could trap fingers or hair. It could also trap, get clothes caught on there. Your bathing suits, it could catch a pocket, you know, a loop of some sort, whatever. So for a commercial pool, immediately close it because you do not want liability, you don't want anyone to get hurt. So for residential pools, there is no code enforcement and they can deny repairs. So you have to do whatever you whatever you can as a business owner or such as myself, the last person to touch the pool because that you are subject to liability. Maximizing flow from the surface is essential as this area contains the highest concentration of pollutants and floating debris. Additionally, minimizing flow through the main drain helps reduce the risk of entrapment. The velocity of water passing through the main drain should never exceed the maximum set uh the maximum rating specified for its cover. So the main drains have numbers on them, and you cannot exceed that flow rate that the cover is designed for, rated for. Surface water removal. So the surface of the swimming pool typically contains this is the third time I've said this now. I didn't realize I wrote that in there three times. My bad, I'm sorry. Highest level of caca, right? Disinfectant levels are often lowest at the surface, which is where users are most likely to ingest the water because everybody hangs out and it gets in your ears and it gets in your eyes, and everybody's spitting water at each other, and it's disgusting, unless it's my pool, and then you can do that because my pools are clean. I'm just kidding. I'm sorry. All pools are toilets, and this increases the risk of contamination to people. The placement and control of surface and return inlets largely dictate water flow patterns. These specific patterns help prevent dead spots, which would otherwise allow algae to grow and cause dirt and debris to accumulate. If you've ever gone to a pool week after week and there's just a little pile of debris sitting in the same spot every week, your flow pattern. I would like to do a die test on a pool. I was gonna talk about the die test a little bit later on. I think it would be kind of fun, satisfying to watch for sure, anyway. The standard practice is to remove 75% of the surface water, um, although some codes permit a 50-50 ratio, and some places have no requirements at all, such as residential pools. But if you are running a commercial pool, maybe just check to see if you have a code of this type of water removal. Make sure that your skimmer or gutter or whatever is more open than the main drain. Now, if you have a gutter system, these operate based on the principle of surface tension removal during periods when the pool is not in use. So there's a little constant flow of water over the lip of the gutter that acts as your skimmer. Precise control of the water level is essential and should not exceed one quarter inch above the gutter lip, and the health department will ding you for that. At least the one in Florida will. This approach ensures continuous surface tension draw from the top layer of pool water. As a result, surface debris and contaminants are efficiently removed and subsequently filtered or oxidized. When in use, the user's actions cause a wave or rolling effect which traps surface water in the gutter for removal and processing. We all know what a skimmer is, right? Skimmers are rectangular openings found at the surface of the pool wall. Their placement ensures that the entire surface area of the pool is effectively skimmed. I love a pool with two skimmers. I just feel like it flows so much better. A floating weir is installed at the entrance to the skimmer body or housing or mouth if you're nasty. This weir automatically adjusts to the water level, enabling continuous. Skimming or sheeting action. When the circulation pump operates, it draws water from the pool, causing it to flow through the pool wall opening and over the weir. The weir acts as a barrier, then preventing water and debris from moving back into the pool when the when the pump is off. I had a guy, I took over a route and he had taken off every single weir door of every pool, and I had to replace, I ended up not replacing all of them because I got sick of doing it, but it's so aggravating if you've ever cleaned a pool without the weir door in the skimmer and it was off and it just goes all over the place. It's real frustrating. Regular cleaning of the skimmer basket is necessary to ensure adequate water flow. I will say that a few more times throughout this. Certain skimmer designs feature an equalizer line attached to the skimmer body and include a spring-loaded check valve. Normally, water flowing through the skimmer keeps the equalizer valve shut, but if the water flow through the skimmer is interrupted, the float valve closes and the spring-loaded equalizer valve opens, allowing water to move from the pool through the skimmer's equalizer line. When the water level drops below the skimmer wall outlet, the equalizer line activates. This system helps the pump maintain sufficient suction flow and prevents loss of prime. Normally they are the equalizer line is plugged and it goes unused and there's never it's never plumbed into the actual pool. I have one that is actually and it works too. I saw it working. The water level got down like maybe two inches below the skimmer opening and it was still pulling water in. I was I was a little bit surprised just because I've never seen one in action before because I've always ever only seen them not used. Imagine that. Kind of cool to see. Felt like I was looking into like a museum exhibit. Alright, so vacuum fittings. Pools require vacuuming to keep them clean. In case you guys didn't know, newsflash. Commercial pools are, to my knowledge, no longer built with dedicated suction lines. So they the last couple brand new ones that I did. This I did a couple startups for a company several years ago. And they all had portable vacuum carts, like a pump and a filter, a harmsco on a cart. That they had them there on site. So I don't know who supplies those. Probably Harmsco, maybe. I don't know, it was a Pentair pump, I think. State, yeah. So um, yeah, so they but or you could use, you know, your back your uh hammerhead or riptide, although they might not be sufficient at removing the super duper fine debris that they can get, that these pools can get sometimes, as these pools are known to do. So for commercial pools that still have a dedicated suction line, they usually had a separate vacuum pump inside the uh backpack. I have done plenty of pools like that, but I don't think that I have ever actually used the vacuum pump to actually vacuum. Well, I in at least not in the last 15 years, maybe even yeah, 15 years, because I've been doing this 25 years. When I first started, I would do that vacuum system vacu through the vacuum pump. But then we all just stopped doing that because of how dangerous it is and hazardous. In pools equipped with skimmers, you can vacuum through the skimmer, and then some wall vacuum outlets are connected directly to the pump's suction side, which causes serious injury or death if these are active during pool use. Operators should keep outlets covered and ensure vacuum lines are off when the pool is open. Covers must always be spring loaded and securely in place. This is especially true for residential pools with dedicated vacuum suction outlets. You want to have that vac lock on there, not a vac lock that doesn't have a door either. Get them a brand new one. Okay, and if they have a zodiac hose, you need to get them that adapter so they're not using that stupid, stupid elbow, that stupid plastic blue angled piece that pops out. That piece makes me mad. I don't know, I'm about to crash out. Yeah, just be careful with that. I I also had a residential pool that I do now where I noticed that the vac the vac line was open and didn't have a vac lock or anything. It just had one of those like plus like just the grates with just just a grate on there, and my net got pulled into it, and there's a little girl that swims there, and I told them I was like, you guys need to like be more careful, keep this closed. And they argued with me about it for a while. It was a whole thing, and then finally they realized, and so now it's closed. And I talked to the grandfather, and he was like, Yeah, it got my arm one day, and I was like, Yeah, I told you guys, I told you there's no way it was for your waterfall. They there's the builder who built that, if they did it that way, they should be arrested. But anyway, long story that I kind of just like rambled on about. All right, let's move on to the collection tanks or balance tanks, which I've never dealt with a balance tank. It's apparently different from a collection tank. I'll get into it. Ready? So at certain pools, commercial pools, they are equipped with the collection tank or the more advanced balancing tank, and they gather water and help separate it from the pool, uh, from the direct suction of the pump, which improves the safety. So the collection tank may also serve other functions beyond its primary roles, such as regulating water levels in perimeter overflow systems. And this is also where your vacuum filters are gonna be inside the collection tanks. Usually we don't add chemicals to the collection tank. This is generally not a good idea, um, especially when there's a vacuum filter present. The chemicals can damage equipment that is downstream. Now the balancing tank, I'm not gonna get there's more detail in it about it in the CPO book, but I'm not, I'm just gonna give you a little summary of it, which it basically collects the water and then stores it later. So when the when people enter the water and the water is displaced, it ends up in the balance tank, which has float valves and something else in there, check valves, I think, and it holds the water in there until the people get out and then it goes back into the pool and it goes back. Fun fact each adult typically displaces about 20 gallons of water. People don't realize that. Be like, why is the water level so high? You're swimming in there. Displace your your mass is displacing the water, buddy. Okay, pool water level control. Have control devices that may be just your basic toilet bowl tank, toilet tank float valve with the arm and the ball on the thing, Roberts, Roberts valve, Roberts, Robertson, Roberts, something like that. Or they can be like your more advanced electrical probes that send signals to your microprocessors, like your level or systems, which I'm currently having issues with one. No, no, no fault to the device itself, kind of like a operator, not operator installer error, because I'm the operator. I never error. Okay, so for pools equipped with perimeter overflows or gutters, the water level shall be maintained at one quarter inch or six millimeters above the gutter lip to ensure optimal skimming performance, which I said. Now your vacuum filters, when these get dirty, when they accumulate their body oils and their debris, the flow of water to the pump drops, and this can lead to pump and or motor failure. It can cause cavitation. Vacuum filters can be damaged if they are exposed to too much suction force over time. And then when these elements break down, debris passes through them, unfiltered water goes back to the pool, maybe it goes through the filter, maybe it ruins your salt cell. Who knows? This also will reduce your water quality, your flow. Um, it's gonna increase the need for chemicals, and people are gonna be mad. Everyone's gonna be upset. Now you have vacuum gauges, which are actually pretty important. They incoming water to the pump. Obviously, we don't want that to be restricted, but it can happen from your hair, people's hair, and other stuff. Um, and this can force the pump to work harder. So we have vacuum gauges before the pump, and this lets us monitor the suction effort. This can tell us when to clean the filter or the pump basket. Um, just like with the pressure gauge, which I talked about in the filtration episode, which was seems like five years ago now, as the as it as the so with the PSI as that increases, it's time to clean the filter. So with the vacuum filter, when the vacuum, not pressure, but when the vacuum rises, it's time to clean the filter. Same thing. So as the debris accumulates, the vacuum, the reading goes up. Okay, and so the heart of the system, the actual heart is your circulation pump. This is responsible for moving the water. And in swimming pools, we use one type of pump for circulating water, and this is a centrifugal pump. We have an impeller which spins along an axis, generates generating centrifugal force to displace water. All pumps share these basic parts, ready. You have the volute or the pump housing, which same thing, but sometimes it's called the diffuser. You have the shaft, which is an extension of the pump motor. You have mechanical shaft seals, a motor adapter and seal plate, and the impeller. So, as I said, the volute is also referred to as the diffuser. Whenever I say volute, I think volut. I don't know why I never had it. It's gross to me. It's just sounds the same. This thing enables the self-priming pump to manage air and reprime automatically. The shaft extends from the pump motor, delivering mechanical motion directly to the impeller, which does this. The impeller facilitates water movement by rotating, drawing water into its center or eye from the suction or influent piping connected to the pool. Through centrifugal action, the impeller propels water outward and the volute or housing then collects it. As the flow velocity increases, pressure is generated, enabling water to exit via the effluent or outgoing piping. This process creates sufficient force to drive water through the circulation system and return it to the pool. And a blocked suction line or the presence of air within the system may result in cavitation, which can cause damage to the impeller to the pump. Rudy has a damaged impeller that he wears as a necklace, kind of like flavor flavor, but it's Rudy and it's an impeller. It's quite comical. Alright, cavitation. What is cavitation? You may have heard it in happening and didn't know what it was. What is it? Well, it happens when the impeller doesn't get enough water to meet its discharge demands. So when it happens, the sound of the pump changes. It sounds like rocks or like gravel bouncing around inside. It sounds like um kind of sounds like one of those rock tumbler things, I think. Bit a bit. Yeah, so this is air bubbles basically like hitting the impeller, making direct contact. And they're very, I mean, it can get hot. So you have that and it and you have that velocity. Well, anyway, whatever. I'm explaining it stupidly now. Sorry. Anyway, the the air bubbles hit the impeller and it erodes the metal and damages it. So some common causes of cavitation. We have debris in the skimmer basket or the pump basket, you have a dirty vacuum filter, you have partially closed or restricted suction line, you have a throttling valve on the effluent line, not properly restricted, so there's too much water going through there, or there's a leak in the plumbing on the vacuum side of the circulation system. Now, cavitation signals an issue, it's an underlying problem, it's like a symptom, there's something wrong. And as I said, can quickly damage the pump or even the motor if you don't take care of it. Now we have pressure gauges. So you install a pressure gauge on the discharging piping. I'm sorry, on the discharge piping directly after the pump. Vacuum goes before pump, pressure goes after. The output pressure measured in pounds per square inch or PSI serves as the primary driving force for system circulation. If the pressure reading is insufficient, the required flow and turnover rates will not be met. The pumps, vacuum, and pressure gauges are instrumental in assessing the performance of the circulation system or determining the what? The total dynamic head. And that's where I'm going to leave you here wondering what total dynamic head is and how you get it. So stay tuned for part two to hear the rest of that. It's going to be very exciting. I'm excited about it. Yeah, and that's it. I hope you guys liked this episode. I circulation is super important. And I think that especially with people not really understanding the VGB thing, people don't understand dead spots. You know, I just want to help. So think about what's happening. You know, think about how the water's moving. If you're having algae issues, if you're having cloudy water issues. It all comes down to these three things that I'm talking about filtration, chemicalization, and circulation. I borrowed that from somebody that's not my that's actually a song. Anyway, like I said, come back for part two, and you can learn how to calculate your total dynamic head and the rest of this information. So that's it. Thanks for listening, and I'll see you guys next Tuesday. Do all the things share, listen, like, follow, subscribe. You can leave reviews on Apple. You can do comments on Spotify. You can email me. You can email me personally at uh my talking pools email is Andrea.talkingpools at gmail.com. The actual show email, if you want to email Rudy and everybody else, that is just talkingpools at gmail.com. Find me on my socials. I'm Andrea Pool Pro on TikTok, Adventures of the Pool Girl, and just Andrea Nanini on Facebook and Instagrams. That's it. That's pretty much it. Thanks, guys. Bye.