Hayward Hydrostatic relief plug question

Sep 26, 2012
7
I have a WS series 8" round dual Hayward main drains in my pool built in 2004. I would like to drain the pool but know that I need to remove the plugs from the pool when draining. does anyone know if there is a o ring on the plug that I will need to replace once I unscrew the plugs? When re installing the plugs do they need to have teflon tape or any other sealant methods or just screw them back in? When I start to drain at what water level in the pool do I need to pull the plugs out? How big of a concern is it for delamination of the finish? I purchased a foreclosed home and the pool has some staining. I would like to drain the pool and acid wash but i dont want to create a bigger problem of the finish popping off if I take all the water out.
 
:wave: Welcome to TFP :wave:

I am not familiar with the hyrdostatic valves, but I would guess there are o-rings ... if so, they should be reusable. If not, then some plumbing putty or teflon could be used depending on the size of the threads.

When/if you need to remove the plugs is fully dependent on your ground water level. If the ground water level is below the pool, then you would not ever need to remove the plugs (in AZ I do not think they even put those valves in as the ground water is VERY low). The safe recommendation is to remove the plug before the pool water level is more than a foot below the ground water level ... up to you to figure that out though ;)

What is the pool surface? It is not normal for a surface to delaminate when the water is drained. If it does, then it likely could have happened with water still in the pool. My pool plaster surface was VERY rough when we bought the house. I drained it and pressure washed all the algae off and did not notice any plaster falling off ... although there were already clearly some chunks missing.
 
It is a plaster finish pool. I had a "experience" with the commercial pool at the resort I manage. We drained the pool to knock down calcium levels and huge sections of the plaster bubbled up after the weight of the water was off of the finish. We had to chip it out and repair, never matches up perfectly after that. I live in Cape Coral Florida (Southwest Florida) and live about 1,000 feet from a tidal canal. My lot is built up though and I would have to believe that would help with any hydrostatic uplift.

I guess if there is anyone else reading this that has experiences of what to expect or a brief cliffs notes on removing the hydrostatic plug please let me know?
 
Well, I don't think the chunks were separated due to the lack of water. Likely the damage was already there and the lack of water allowed them to flake off. Sounds like the surface was beyond time for repair / replacement anyway.

Let me back up. What kind of staining do you think is on the pool? Is it metal staining or calcium scaling or organic (algae) staining?
 
I would say that it is mostly metal staining due to the orangeish streaking leading from the location where the metal was sitting in the forclosed pool for what looks to be quite some time. The pool is a "volleyball" style with the deepend in the middle and two shallow ends. I had metal at each shallow end that over time left a trail that streaked from the shallow ends all the way to the main drains. I tried to use dry acid in a sock but it had marginal results and was going to leave a ruff etched swath. Lately I have seen other other orange spots forming around the pool, i tried to put a tri chlor puck on them overnight and I did not like the results. Might be the metal trying to settle back into the finish. I have also noticed that the pump basket,filter element, and the insides of the pipes when I take the returns off is stained orange.

5ppm chlr
100 - Alk
400-500 cal
7.4 ph
cya -100
city water
1.5 hp Pentair Superflo
Pentair CC150 cartridge
Hayward erosion feeder
 
What you are describing with the commercial pool was delamination and has nothing to do with hydrostatic pressure.

If you have a Hayward Hydrostatic relief plug in place (not sure how you would know this unless you dove into the pool and removed the drain cover), it will relieve the pressure when you drain the pool. Most commercial codes require these however we only put them in when there is the threat of ground water.

The potential damage from the pool structure floating is far greater than plaster delamination. You need to be ABSOLUTELY certain there is NO chance that the pool will float if you are going to drain it.
 
If it is metal stains, then a chlorine puck will not remove it. You want to try using crushed up vitamin C tablets in a sock ... or ascorbic acid.

There are also treatment methods for metal stains that do not require draining the pool that are used if the stains are very wide spread. If your stains are pretty localized (I know you said you have a streak), you may want to try the vitamin C in a sock first as you may be able to get most of the staining out without draining the pool or performing an ascorbic acid treatment.
 
What you are describing sounds like iron. You can test it with a vitamin C tablet and there are extensive topics on this site about Ascorbic Acid treatments along with other options. Draining and acid washing the pool may not solve the problem but it will prematurely age the plaster and make it rougher.
 
renovxpt said:
What you are describing with the commercial pool was delamination and has nothing to do with hydrostatic pressure.

I think what they meant was that once the water was drained, the pool water was not holding the plaster up against the shell, therefore it was able to bubble/flake off. Nothing to do with the water outside the pool. Granted draining the pool was NOT the cause of the delamination, but did allow the problem to be discovered.
 

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Yes, there is definitely a plug down there I did confirm. I understand that popping the pool is worst case, so to me pulling that plug out is going to happen I am not clear on, if the water table is down I dont want to let a ton of water under the shell if I pull the plug out to early, and the other hand I dont want to pull it out to late if the water table is up.

I am aware of the abscorbic acid treatment but I am still using the same water since the house was purchased, who the heck knows what could be lurking in there.
 
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