Fighting Algae with Borax

Here's an update, I still have 50 ppm borates in my pool.
Sunday, my pool was crystal clear and I had to add a lb of cya, the level had dropped below 30ppm. Sunday evening a storm moved in and I closed the pool cover.
This morning I opened it, to a green pool, after about 60 hours.

no FC, no cya, ph 7.5. I'm so irritated I'm thinking of filling the pool with concrete.
Whatever kind of algae is in my pool is proving to be impossible to eliminate completely. So now, I'm back to square 1, adding bleach in crazy quantities.

Curious and jumping in here....do you have an swg? If you don't, I would consider trying that BEFORE filling in the pool with concrete. All the water going through the cell gets a brief shock so intuitively, it should work for you.

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Originally Posted by topless

Here's an update, I still have 50 ppm borates in my pool.
Sunday, my pool was crystal clear and I had to add a lb of cya, the level had dropped below 30ppm. Sunday evening a storm moved in and I closed the pool cover.
This morning I opened it, to a green pool, after about 60 hours.

no FC, no cya, ph 7.5. I'm so irritated I'm thinking of filling the pool with concrete.
Whatever kind of algae is in my pool is proving to be impossible to eliminate completely. So now, I'm back to square 1, adding bleach in crazy quantities.

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What was your FC BEFORE you covered the pool? Also, why did your CYA level drop? If the chlorine was low before you covered the pool borates by themselves won't prevent algae.

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Originally Posted by waterbear

What was your FC BEFORE you covered the pool? Also, why did your CYA level drop? If the chlorine was low before you covered the pool borates by themselves won't prevent algae.

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I'm sure the FC was fairly low after a day of swimming, I checked it in the morning and it was about 3ppm. The storm came in very quickly and if I had just added another bottle of bleach before closing, I'm sure I would have had no problem.
I added cya back into the pool, dropped the ph to 7.2 and shocked it to about 40ppm yesterday. This morning I could see the bottom in the 6' area while brushing. I expect to have it cleared out by tomorrow.
I don't know why the cya disappeared unless the algae already had started to grow and bacteria was consuming it. It had been pretty level for the last couple of weeks, then suddenly started dropping over the weekend.
I was really surprised how quickly it turned green and cloudy.

It is my understanding that the bacteria that consumes the cya is found in soil in particular. Maybe that bacteria got swept into your pool even with the cover. Not an expert, but this is what I have gleaned from all of the research I have done on it....

That's possible, my pool cover setup is almost 20 years old. Back then they didn't concrete the bottom, it's dirt.

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.

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.

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.

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.

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

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.

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.

Thanks for the info on the borates finally zapped the alge and the pool is soooooooooooooo clear.

jen

Here's an update for 2008. I closed my pool last year late, waiting for the temperature to get down below 55 degrees. I did exactly what was recommended, including adding polyquat for the first time. We had an extremely long wet winter & spring. I finally opened my pool in late May and the water was clear enough to see the main drain. However, all chlorine was gone and the water was just starting to cloud. I added 1.5 lbs of CYA, 3 bottles of bleach and started the pump. I tested for borates, it was still 50 ppm.
We didn't swim until the last week of June (I'm a sissy when it comes to water below 78 degrees), but I have had zero algae, and used about 1 bottle of bleach per week to keep the water crystal clear. Only needed more when cottonwood trees were covering everything, this year was really bad because of the excessive amount of rain. We passed the yearly rainfall average by the middle of June.
Do borates inhibit algae growth? Yes.

I regret to say, I found mustard algae in my pool today. Not real bad, but It's back to 24ppm shock for a few days.:mad:

Sorry to hear your algae came back.

Borates (boric acid) are a mild algaecide, not a strong one like sufficiently high levels of chlorine or copper (but that can cause staining). It's possibly a little weaker than PolyQuat though that is just a guess. Mustard/yellow algae takes about twice as much chlorine to kill it as regular green algae and it probably takes a stronger algaecide to inhibit it.

A chlorine level that is 15% of the CYA level seems to be roughly the level that inhibits its growth and is roughly the "Max" column in Ben's Best Guess CYA Chart. Killing an existing outbreak can take an FC level that is 60% of the CYA level over several days and making sure that you get behind light niches, soak all poles, etc.

Richard