The Danger Zone: Why Filter Cleaning Requires Real Safety

Pressure doesn’t look dangerous—until the instant it is. We take you right to the two moments that matter most in filter service—when the lid comes off and when it goes back on—and show you how to turn a risky task into a safe, repeatable routine.

We start by reframing the filter as a pressure vessel, not a harmless canister. Sand filters are usually one-piece and lower risk; cartridge and DE filters come apart, rely on clamps or locking rings, and can fail if misaligned or under-tightened. You’ll hear why modern safety designs like the Aquastar Pipeline’s interlock are so effective and how to apply the same logic on any system: power down, bleed air, drain, and verify zero pressure before loosening hardware.

From there, we share practical safeguards that work in the field. Put automation in service mode, move Intermatic trippers, or cut the subpanel, but don’t stop there—remove the pump lid so the system can’t prime even if a glitch starts the motor. We talk through clamps in detail: reading spring-barrel nuts, preventing cross-threading with a touch of lube, knowing when a clamp is cosmetic-ugly yet structurally sound, and when to replace hardware for peace of mind. On restart, we step back, open the air relief, and wait for water before approaching. A spiking gauge is your red flag for a blocked return or a clogged salt cell; shut down fast, clear the path, and protect the tank.

• treating the filter as a pressure hazard
• relative risks of sand, cartridge, and DE filters
• turning off power and automation service mode
• removing the pump lid as a fail-safe
• bleeding air and safe startup distance
• clamp types, tightening until spring coils meet
• avoiding cross-threading and when to replace clamps
• spotting dangerous pressure spikes and return blockages
• quick priming tips and avoiding automation glitches
• training techs to follow a standard safety checklist

Learn more at swimmingpoollearning.com  
On the banner, there’s a podcast icon—click for the archive  
Learn more at PoolGuyCoachin

Support the Pool Guy Podcast Show Sponsors! 

HASA 
https://bit.ly/HASA

The Bottom Feeder. Save $100 with Code: DVB100
https://store.thebottomfeeder.com/

Try Skimmer FREE for 30 days:
https://getskimmer.com/poolguy 

Get UPA Liability Insurance $64 a month! https://forms.gle/F9YoTWNQ8WnvT4QBA

Pool Guy Coaching: https://bit.ly/40wFE6y

Chapters

• 0:00 Why Filters Are Truly Dangerous
• 3:31 Sand vs Cartridge vs DE Risks
• 4:57 Startup Hazards And Bleeding Air
• 6:38 Aquastar Pipeline Built‑In Safeties
• 7:51 Absolute Rule: Power Off Procedures
• 9:51 Extra Safeguard: Remove The Pump Lid
• 13:17 Clamp Types, Tightening, And Wear
• 17:08 Safe Restart, Air Relief, And Blocks
• 20:24 Final Checks, Training, And Resources

Transcript

SPEAKER_00: 1:03

Hey, welcome to the Pool Guy Podcast Show. In this episode, I'm gonna talk to you about some safety around pool filters, and I'll go over specific things that could go wrong, of course, plus some things that I think are important to keep you safe when you're doing a filter cleaning or servicing or working on a pool filter. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support. From me, I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at swimmingpoollearning.com. I think it's wise to look at a pool filter as kind of like a pressure cooker in a kitchen somewhere. If you ever use a pressure cooker, you know that maybe you have a background working in a restaurant or something when you were younger. And if this thing were to get too hot and under too much pressure, it could explode. And of course, this is a dangerous situation. And I think a pool filter should be seen in the same light, that it is something that's under a high amount of pressure, and if something goes wrong with it, it could explode, potentially causing injury and death. And it is the most dangerous element on your pool equipment. Now, some filters are more dangerous than other filters. I want to clarify that there are filters that are under a lot more pressure. And I would say sand filters are probably the safest filter type because they're one complete unit usually, and typically you don't take those apart to clean them. You just take them apart to change the sand or check the laterals, and they're probably what I would consider to be relatively safe back there. The cartridge filters and a D filters are the ones that pose more danger because you take those apart to clean them, and they have, of course, a clamp or a ring that holds them on, which under pressure could explode on you if not put on correctly. So with that said, I think it's important to look at the filter as something that's a hazard back there in a way, and as something to be treated as such. And I think if you take it lightly and don't think of it that way, you could, of course, leave yourself open for potential danger by being kind of lax or laxadaisical about the danger presented by this object under a lot of pressure, under a lot of water pressure, that is. And one thing to note about the filters is that in most cases you'll never have a problem if you follow the procedures and if you follow the rules of anything. That's kind of how it is out there. When things start to get older, of course, replace them, and always err on the side of caution. Whenever I clean a filter and I put it back together, and I open up the airbreeder valve and I turn on the pump, I kind of always back away to a safe distance. It's kind of like a habit I develop. It's just because I'm maybe paranoid. I've seen, you know, too many, I've heard about too many of these accidents happening when you turn on the filter and the clamp fails and the filter explodes at that moment, which is probably pretty rare again if everything is working correctly. But still, I guess I'm a little paranoid and I'll step back. I'll take a few steps back or move away from the filter entirely until I hear the water coming out of the air relief valve. Then I know it's pretty safe. Because there is a lot of air in there when you start it up, and so to me, I think that's a danger point when you put the filter together, put the clamp on, turn on the pump, and you need to hear the hissing, the shhh, and then water comes out, and then I think you're safe at that point. And again, I always treat it that way because it's one of those things the label on there is true. If that were to explode at that moment, you could of course be severely injured by the top of the tank hitting you. And I've heard of pool pros that were putting the tank on and then they didn't turn the timer off. I'll get to that in a minute. Then it came on while they're putting the clamp on, which is also a dangerous situation. So most of the danger you're going to encounter with the filter is when you're taking the lid off, to clean it, and also when you're putting everything back together. I just want to clarify that and emphasize those are the two danger points of filter cleaning. Now, the Aquastar Pipeline filter is an interesting filter that has built-in safety mechanisms to kind of help you navigate the danger when you take it apart. So, for example, if you have an Aquastar pipeline filter on your route, or if you put one in, if you take that ring off to clean the filter, but you don't release the air in the filter first, that that ring won't spin free, which is a really cool safety aspect. I really like that, and I think more manufacturers should introduce that with those filters with that plastic ring type lockdown ring. Not the bolt and spring knot clamp type filter, but the ones with the plastic locking ring, that'd be a great safety feature. So with the Aquastar pipeline filter, in order to clean it, you have to open the air bleeder, then remove the drain and drain the water out, and then that will depressurize the tank, and you can actually spin that locking ring and remove the lid. It's really nice, and this is kind of the same procedure you'd want to use with a four-quad cartridge filter or a D filter as well. But of course, step one should always be turning off the equipment so that you don't have the pump accidentally coming back on during two critical junctions, which is one when you're getting the lid off the filter, and two when you're putting the lid back on the filter. These are the two areas where it becomes critically important that the filter pump does not come on at any time during these two moments. And these moments could be split seconds, by the way, and this could be you know a potential fatal thing that you do or a fatal error that you can make. So the first thing I do, of course, is I if it's an interromatic timer, I'll take that timer and I'll pull the dial towards me and I'll spin it away from the on-tripper. You can also remove the on-tripper, a lot of pool guys do that as well. And you can, of course, kill the power if there's a subpanel there or a kill switch to turn the power off to the pump so that it's not going to come on at any point during the filter cleaning. If you have the standalone VS pump, hit the off button and turn that pump off. It's a good idea also to turn off the subpanel if you can find it. I don't think many pool guys go to the main breaker and turn off the pool equipment there. You can do that as well. Sometimes it's inconvenient is in the garage or it's on the other side of the house. As long as you can turn off the pump at the pump itself, that should be enough because there's a secondary thing that I'm going to tell you to do in a moment that's going to, of course, prevent any kind of accidents. But primarily turn off the pump, turn off the power to it, and if you have an automated panel, put it in service mode. That's the 24-hour off mode, basically, 24-7 off mode. And then you can safely open up the air relief valve on the filter, open up the drain, and then take the filter lid off. It's a pretty easy procedure, and it's something that you should do at every single filter cleaning. Now, the secondary thing that I'm going to tell you to do here, which is going to prevent any kind of accident before you take the filter lid off, is remove the pump lid on the pump. Now be careful that you're not below the water level or below sea level at the equipment. The first thing you want to do, of course, if the equipment is below the pool water line, is turn all the valves off to the return and suction so that that's a closed system. 95% of the pools are going to be at the same level or above the pool water line. That's not a problem usually. So take the pump lid off, and now you can easily proceed with removing the filter ring or the filter clamp and getting the filtered lid off without having to worry about any kind of danger with the system coming on and causing injury. This is something I've been doing a lot lately, removing the pump lid on the systems. I had a couple scares. I don't know exactly what the error was, and I've called Penter on this before, and they couldn't figure it out either. It's when you have an older Penter Intelliflow connected to an Intelli Intelli. It's not the Easy Touch, it's the IntelliTouch panel. And when that's connected together, there's been a glitch I've had happen to me, and you may have had this happen to you as well there, where you put the system into service mode, and you everything's off. And then you go to take the filter apart, whatever, doing whatever. I have had this happen when I clean the assault cell as well, and then all of a sudden the the pump comes on and everything, you know, comes on while it should not be coming on at all. And this is something that I'm not sure exactly what the glitch is, but that's happened, and so what I've been doing since this has happened to me on a couple occasions when I'm doing something around the pool, filter cleaning, salt cell cleaning, whatever, I'll take the pump lid off. And if the pump comes on, so what? It's not going to be able to prime up the filter or pull water through and flood everything with the salt cell off the plumbing at that point. And I think it's something that you should incorporate into any time you're doing service on the filter or maybe a salt cell cleaning, it's just remove the pump lid. Now, of course, this will cause air to go into the system and be aware that in certain situations you may have priming issues afterwards, you know, you may have tough trouble priming it, but in most cases, I don't really have this problem. There's like one or two pools that are like super far away from the equipment where if I were to do this and try to prime it, it takes a little bit longer. You can always, of course, prime the system from the spa and then turn the valves back to pool mode if you have any problems with air in the pool line. So not really a problem, but it's an extra level of safety, in my opinion, that should be taught to all the pool techs out there, all your employees, that before you take the filter lid off, take the pump lid off. And before you put the filter lid back on, of course, and tighten everything up and turn on the system, then you put the pump lid on, fill it with water, prime it up, and you're good to go. Now, this is really simple to do, and more people should be doing it because again, without that pump lid on, there's no way that filter could fill with water, fill with air, pressurize, and cause any kind of accident. This is also a good time when you're doing the filter cleaning, especially with the spring barrel nut clamp, which is on a lot of the DE filters and cartridge filters out there. The four by cartridges, most DE filters have this clamp. I like this clamp because it does have that built-in safety. And if you look at the actual diagram on that clamp, it tells you to close it and keep turning it until there's no gaps in that spring. And I really would advise you to do this. Now I've had some accounts where I've taken over the pool and I get back there and I see that the homeowner was doing the filter, and I look at that clamp and I look at the spring that's in that nut, and I it's like totally open, like there's gaps on there, and you know, I'm sometimes amazed that the lid hasn't blown off the filter yet. So the good news is you have to put it on extremely loose for that actually to blow off. And and from my experience of taking over pools where the homeowner put that on, and to me, it's very loose. So, of course, tighten that up. If you're using the multi-torque socket set, which I highly recommend by the way, if you are interested in these, go to multi multi-tork multi-torque.com, and this will allow you to put these spring barrel nuts back on super fast. But what I do when when I'm doing when I'm using the multi-torque is I'll put it on there, and then once it gets to the end of it, I'll take the drill with the multi-torque socket on there, and I'll kind of spin the drill three or four times to kind of manually tighten up that spring barrel nut. And one thing that you can also do, by the way, to preserve that and allow that to last longer, because those are pretty expensive, the clamps are expensive, they're one solid piece, is to get a tube of magic lube. And the magic lube tube actually is the exact diameter for that threaded bolt to fit into the magic lube lid, and put some lube on there, and then when you put this, when you put the spring barrel nut back on there, you're not gonna strip it. Sometimes you put it on if you don't do that and you're putting it on, you can actually put it on cross-threaded, and that weakens the clamp. It also makes it nearly impossible to get off the next time you clean the filter. So be sure that you don't uh cross-thread that clamp with the spring barrel nut, and it's something that does happen out there. So when you do run into a situation where that has happened, simply replace that clamp at that point. Now there are a few occasions where you can get away with replacing just the bolt and the actually the nut and the spring barrel, but really for overall safety, whenever that clamp seems to be compromised, you can kind of see it too if it looks like it's kind of loose a little bit as far as you know the threaded part, how it fits into that clamp. Whenever I see something that looks compromised, and just a word of caution here, Hayward had a really bad run of clamps, and they may look like they're like 50 years old or from the Titanic because all the paint is chipping off and it's getting really cruddy looking. Those are perfectly fine, it's just a manufacturing defect that they had these clamps they made, it had a run of them for many years. So you may get a Hayward D filter cartridge filter with one of these really thick black clamps on there, and you may think, well, this thing is so old it's compromised, but it's really not, it's just really poor manufacturing at that point, causing that clamp to look like it's you know made in the 1950s. It's really probably just like three or four years old in a lot of cases, it just looks really cruddy, it's still perfectly fine. And I prefer the Hayward clamps myself because they're like super solid, Hayward and Jandy. The Pentair clamps, I mean, they look flimsy to me, but they've they work pretty well. The Hayward clamps and the jandy ones are just solid, solid clamps where you really don't have to worry too much. So the last thing I would say is that when you do turn on the filter, put the lid back on, the pump fill it up with water, turn the system on, open up the air bleeder. Some air bleeders are better than others, of course. The pentare ones are the best because they're gigantic, let a lot of air out fast. But this is where the danger of restarting is if the clamps on correctly, if there's something compromising the clamp and or the ring that you're putting on, and the air is filling up the filter at that point. Here's where it could become explosive with the air getting the air being evacuated out of there. So this is what I always walk away when I'm bleeding it out until I hear the water, just because I'm a little bit paranoid, and you never know if there's some kind of mechanical failure with the clamp, even though it looks good. So this is where I step back a little bit until water comes out the top, then I know I'm in the clear. Now I'll give you a couple danger points here too when you turn the system back on, and this could happen. There can be debris or leaves or something that gets into the return line sometime between somewhere between the filter and the return line. You could also have blockage in the salt cell. That's why I recommend that whenever you do a filter cleaning, you also take the salt cell off to clean it. Because a lot of times, and also if you see this happen, you want to make sure you turn the pool off right away. And of course, if there's a salt cell, take it off and inspect it. But sometimes debris will bypass everything when you're draining everything out. This has happened to me, of course. That's why I'm telling you this. This is the possibility that if you're in a location where there's a heavy debris load, you know, like there's um cypress trees nearby, this is this is the actual incident that happened. The cypress tree tree leaves are in the filter, completely filling up the cartridge filter. And then when I removed everything, some of them got into the return line in between the salt cell and the filter. The bottom line, if any debris gets into the return line at that point, which can happen, you turn on the pump, the pressure gauge could go from say zero to well over 30 to close to 40 pretty rapidly. So turn everything off and then check for something blocking the return line at that point, which can happen. Doesn't happen all the time, but there is a possibility that something could have gotten in there and could be blocking the return line. This is a dangerous situation because the water has nowhere to go, the air has nowhere to go really, except in the tank, and that keeps expanding to the point where it can actually explode, even with a really tight clamp on there. And this is more typical of a cartridge filter when you remove the cartridge, you're you have a direct opening to the return line at that point, and that could be full of debris D. Not quite as often because when you remove the grids, there's it could happen if the tank's not draining properly, or if you know the backwash valve when you go to drain it is not working, or if you don't take the drain off, that could happen as well. So just be aware that you can cause an obstruction of the return line while you're cleaning the filter, and to be aware of that with the pressure gauge. Now, when you turn on the filter, you should have a normal pressure, and it should go to 15, usually or 18 on a D filter, and then you're perfectly safe there. You know, close the air bleeder and everything's good to go. Check for leaks, make sure there's no leaks in the O-ring. And of course, I can address some other aspects of the filter in a different episode, but I just wanted to focus on really being safe out there to prevent those two danger points when you're taking the filter lid off and when you're putting the filter lid on. These can be a very dangerous part of the filter cleaning. So, of course, follow this caution and you should be really safe out there. And your employee your employee should also be safe out there doing the filter cleanings. If you're looking for other podcasts, you can find those by going to my website, swingingprolearning.com. On the banner, there's a podcast icon. Click on that, and there'll be a drop-down menu over the podcast for you there. And if you're interested in the coaching program that offer, you can learn more at PoolGuyCoaching. Thanks for listening, poolguy coaching.com. Thanks for listening to this podcast. Have a great rest of your week and God bless.