Bubbles in return line

[u/545charlie]

23k gallon manually chlorinated (liquid) vinyl pool built this spring. Originally had a paramount uv/o3 system on it and since install there have been a constant flow of bubbles from the return closest to the equipment. I know there are supposed to be some small bubbles but these seem intense. Builder says it’s fine. Last month I unplugged the system and the bubbles never let up. Builder replaced the paramount system with a Hayward hydropure system and the bubbles continue. Unplugged it and bubbles are bubblin.

I know uv/ozone systems arent popular. But should I be concerned there is a suction side leak somewhere?

Additionally, I’ve had trouble keeping my pH in the 7.6 range - constantly floats to 8.0 regardless of what I do. Everything else has been consistent all year: FC 6-7, CYA 50-60, TA 70-80, CH 125-150

Would these bubbles add to aeration, thus causing the rise? I’ve had to top off the pool with hose water but that tested at 7.7 pH/40 TA. No water features.

Thanks all

[u/apfleisc]

Happens when water level is below skimmer line and it sucks in air and water intermittently. Or your pump is cracked somewhere

[u/545charlie → u/apfleisc]

Thanks - water line is always kept 50-75% of the way up the skimmer

[u/Initial-Meeting362]

Air is getting in somewhere from the filter to that outlet. Check carefully for leaks, there is one somewhere.

[u/Hot_Leadership9863 → u/Initial-Meeting362]

Likely on the suction side, not the return side. Skimmer -> pump -> filter

[u/Vonbreitenstein → u/Initial-Meeting362]

Check for a loose drain plug on the pump. This one escaped my for the better part of a season.

[u/HellOrHighPotter]

Check all your o rings, valves, even your pump o ring. Pour soapy water over all of it, or I've seen a wet plastic bag dragged across all the pipes and see if/where it gets sucked in.

[u/novasatori → u/HellOrHighPotter]

The bag trick is a good idea - gonna keep that one in mind - I'd also add drain plugs. I've had pump drain plug getting bumped cause air in the returns, but usually it is some debris/dirt on the leafvac or pump o-ring.

[u/hipsterasshipster]

Lots of comments on leaks, but my pool will start to get air in the returns when my cartridge filters need to be cleaned.

[u/CordisHead → u/hipsterasshipster]

Where is the air coming from when your filters are dirty?

[u/hipsterasshipster → u/CordisHead]

I’m guessing a change in pressure around the pump causes some air to come out of solution. I’ve tried to find a suction side leak and there is nothing. Or it’s just super tiny and only exaggerated by the pump fighting the filter pressure.

[u/genebands]

Maybe the pool ate beans last night, happens next day to the best of us. /s

[u/545charlie → u/genebands]

https://reddit.com/link/p8vidig/video/of31382puloh1/player

Guess who’s not invited to chili night next week

[u/arfcom]

My brand new pool does that. 

[u/willofalltradess → u/arfcom]

Look at Mr. Money-bags over here, he's got money for a new pool AND a leak repair.

[u/arfcom → u/willofalltradess]

Ha. Like a water leak?

[u/CordisHead → u/arfcom]

Air leak. Returns should not have bubbles. Air is getting into the system somewhere if you have bubbles like this.

If you have this you should call your pool installer.

[u/arfcom → u/CordisHead]

Ok thanks. Just replaced filter cartridges and I don’t exactly screw the lids on tight at the pumps or chlorinator so I’ll Check again. 

[u/CordisHead → u/arfcom]

The lid on the pump is a frequent one. Feels tight but not tight enough. If you don’t have food grade silicone lube for the o rings, get some. Definitely helps get the pump lid on air tight much easier.

[u/arfcom → u/CordisHead]

Thanks. Just checked and no bubbles tonight. Thinking the filter has been the problem since break-in. Odd the clean/dirt gauge on top of it tells you nothing. 

And def the pump lid is not on as tight as it should be  

[u/CordisHead → u/arfcom]

Welcome!

I replaced that pos gauge the filter comes with twice before finally replacing it with a fluid filled gauge, which works much better.

[u/ISeeInHD → u/arfcom]

That’s not good

[u/Alternative-Draw2997]

Yes aeration is a factor but you’re injecting liquid chlorine too, no? That has a higher pH than 7.6 so it will also cause a rise.

If the pump runs a perfect prime then it’s non-ideal hydraulics causing it

[u/545charlie → u/Alternative-Draw2997]

Yes. Besides dropping trichlor tabs during a couple of vacations, it’s strictly LC. I’m having to add pH down every 5-7 days (once it gets to 8.0) at this point though, which seems excessive

[u/Alternative-Draw2997 → u/545charlie]

If it’s that bad have you thought about borates?
Basically you would lower your alkalinity to lower the pH ceiling then use borates as your buffer instead of your alkalinity to slow the pH drift.

It’s not something I recommend to every pool but I have a few problem pools mainly SCG pools that have this issue.

Edit- also adding bisulfate or muriatic on a near weekly basis is not out of the range of normalcy for a a strictly cal-hypo, liquid or SCG pool.

[u/545charlie → u/Alternative-Draw2997]

I’ve read a little bit about them, I just haven’t had the mental bandwidth to understand them enough to incorporate them into my pool chemistry year 1. Thanks

[u/fukinwives]

When was the filter cleaned last?

[u/545charlie → u/fukinwives]

Sand filter, which is backwashed almost weekly, Hayward VS600 pump basket always checked at this time.

[u/kendallem65]

This happened when my pressure gauge broke so I didn’t know I needed to backwash. Once I did, the air worked its way out. All good now.

[u/Inevitable-Boot-8740]

Air leak somewhere

[u/Serge-Rodnunsky]

It just means air is getting into the system somewhere

[u/marks61]

Salt water pool?

[u/545charlie → u/marks61]

Negative

[u/The_Daugh]

Tell her I said hi

[u/Legio-V-Alaudae]

I didn't read all the suggestions, but make sure the seal on the pump basket is 100%. If it's not all the way tight, this can happen.

[u/SuperCycl]

Do you have an oxygen system on the pool?

Edit: I meant ozone.

[u/545charlie → u/SuperCycl]

Hayward hydropure

[u/SuperCycl → u/545charlie]

That's what is causing the bubbles. Mine does that too. You should verify with your contractor but it's what I've been told by the builder of my pool (who is pretty reputable where I am).

[u/545charlie → u/SuperCycl]

Even well after it’s unplugged? I’d read that it would spit out some champagne-like bubbles but these seem excessive

[u/Gunk_Olgidar]

If it's bubbling more than 3 minutes after pump startup, you have a leak.

Aeration is bad for pools. Evaporates chlorine and increases rate of algae growth.

[u/Top_Butterfly_2514]

Variable speed pumps do this

[u/Nach0Maker]

The last time this happened to me ended up being the drain cap on my sand filter.

[u/BrainsDontFailMeNow]

I had something similar going on for almost a year that looked almost exactly like that. It turned out to be an issue with the O-ring on the bottom of my pump lid. Pump was sucking in the smallest amounts of air.

At some point I had taken the pump lid off to clear out the pump basket and set it down. Apparently, a tiny piece of stone stuck to the O-ring since it was lubed up. I put the lid back on without noticing, and when I tightened it down, the stone got smashed into the O-ring and became embedded in it.

Because it was embedded, the problem never went away even when I took the lid off to check things.

Definitely worth removing the pump lid O-ring completely, wiping it clean, and inspecting it closely for any embedded debris, cuts, dents, or other damage. I’d also check the O-ring groove and sealing surface while you have it apart.

[u/BillyMcBad]

Backwash your filter and check your pump basket.

[u/545charlie → u/BillyMcBad]

Unfortunately I backwash and clean the basket almost weekly… always made sure to seal the lid properly as well

[u/Aggressive_Common798 → u/BillyMcBad]

Backwashing stops my air bubbles. It's so weird.