Fighting Algae with Borax

[Tredge]

Sorry to hear about your trouble.

The borax is still working miracles for me. My pool maintenance is down a ton...I havent even brushed once all summer!

I do have an SWG though.

When the pool is perfectly still I cant tell if there is water in it or not. Its that clear.

[waterbear]

People tend to forget about a piece of equipment in most inground pools, the hydrostatic relief valve. If you are having a lot of rain and the ground is saturated the valve can open and allow groundwater into the pool. This is one of the ways that they are supposed to work. It can dilute all the chems in your pool and can lead to an algae outbreak, even with a covered pool.

[salinda]

Curious about this: What about areas like mine that have a relatively high water table? My water is pretty perfect but in the winter is when the problem is the worst around here. People get flooding in crawl spaces and such, so the 10 ft deep end of my pool is certainly under the water table. Does this mean the valve is open a lot in the winter? If that groundwater with its cya-eating bacteria is getting in, that might explain the cya losses I have been experiencing every winter.

[topless]

Hydrostatic relief valve? I've never heard of it before and don't know if I have one. Where are they usually located?
This area has gotten so much rain this year that for the first time in the 7 years I've lived here, the sump pump has run, a lot. So, I know the ground is more saturated than anything I've experienced before.

[Sumo1]

Our church pool is drained each year and when it's empty, groundwater comes up through the hydrostatic until it finds its own level. When the pool is full, the weight of the water and the water pressure is enough to keep it closed. The hydrostatic valve is located beneath the drain grate in the deep end of your pool. You have to remove the grate to see it. The valve on the church pool is a 1 1/2" pipe with a cap that is attached with a hinge on one side. There is an O ring below the cap and it is spring-loaded so that the cap is closed when something is holding it down (ie. water/pressure). During the winter, we put a large rock on the valve to slow down the influx of water. As I understand it, almost all pools built in the last 30 years have them, and they are probably required by local building codes in most areas.
Hal

[topless]

I know exactly where the valve is now, I wondered what that fitting was under the main drain grate.
I realized I have another path for dirt into the pool. When this pool was installed, it has no concrete on the west side. On the other side of the brick lip are landscape timbers and they are cut into a berm that rises 5-6 feet above the pool in about 15 feet. I vacuumed the pool today and that side had a lot of dirt on the bottom. Even with the cover closed, a hard rain could wash dirt down the hill and into the pool. One of my projects was to dig out that side and put a retaining wall 3-4 feet back so we could walk around the pool. Now, I have another reason to get that done.

[Tredge]

I dont have a valve like this. I have a very old concrete pool and the bottom intake is all sealed up now. The pluming under the pool has been broken long since before I owned the pool.

Doesnt really matter as I am on top of a gravel area with a low water table.