Adding Hydrostatic Valve(s)?


New member
May 6, 2021
Good Evening,

First off, thank you all for the exhaustive information on this site. I have learned more about water chemistry than I ever wanted. I am a longtime browser, but infrequent poster.

I bought a beautiful home in 2016 with an inground 'double-kidney-shaped' gunite pool @ 20,000 gallons which was installed in 2002.

The pool is VERY shallow (maybe 80% is 4' deep. The 'deep' end is 6.5' deep but has a floor diameter of about 6 feet.

During the last few years I have replaced the heater (2021), upgraded to a variable speed pump (2020) and replaced the pool light (2017).

I am very comfortable in maintaining and repairing the pool, and while it still looks WAY WAY better than most pools in the area, it is time to do some plaster work.

It appears that the coping and tiles were replaced right before I moved in, but the plaster has some rough spots where it is pitting and some of the areas have eroded down to the gunite.

I just closed the pool for winter (Dang Michigan weather), and plan to do a good acid wash, some minor repair work, then try sider-crete's roll-on plaster to bring the surface back to its former glory. Hopefully this will last me another several years before I actually have to bite the bullet and have the entire pool redone professionally.

My question -

The pool only has one hydrostat which is obviously in the main drain, but I have been told that the single hydrostat may not be enough to keep the pool from floating should the water table rise and I have the empty pool in my back yard for a couple weeks while working on it.

I would feel more comfortable installing ANOTHER hydrostat at the other end of the pool just in case.

How difficult would it be and what tools do I need to install a 'new' hydrostatic valve through the floor of a gunite swimming pool? I did some research and couldn't find much information for this project which leads me to believe it may not be feasible.

Any comments would be appreciated!

John Q


TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
Morris Cnty NJ
Difficult to do without experience. They are usually placed in drains to allow service or some other vessel to use threaded connection. One drain would likely be fine but ground water needs to be known. If it's gonna sit long term then either drilling relief holes to patch with hydraulic cement and plaster or cutting the gunite and setting new valve bodies
Thread Status
Hello , This is an inactive thread. Any new postings here are unlikely to be seen or responded to by other members. You will get much more visibility by Starting A New Thread