Algae eating my lunch!

I have an in ground gunnite (plaster) pool, 18,000 gal. Until recently, it was saltwater. The circuit board that tells my chlorine generator to produce chlorine went caput, so my dear sweet husband decided that we should try Pristine Blue rather than replace the faulty part. Soon after switching to Pristine Blue, I began having a problem with persistent black algae and mustard algae as well as cloudy pool water. After several hundred dollars and a lot of chemicals, the black and green algae have almost completely covered the floor and walls of my pool. Searching the web led me to think my only option at this point was to drain the pool and give it a "chlorine bath". However, this evening after talking to a neighbor (who recommended this site), I added about 10 gallons of 6% bleach and brushed thoroughly (again). I am definitely going back to salt water, but need to know if I am doing the right thing with the bleach...my arms are starting to look like Ahhhnold with all the scrubbing! Please help, before I get a few dump trucks full of dirt....

Welcome to the Pool Forum!

You are definitely on the right track by adding bleach and brushing. In order to help us help you may we please ask you to complete our pool info chart: Pool Chart Entry Form

It will give us information about your specific pool and help us tailor our advice to your specific needs.

For now, keep your pump running 24/7, keep adding bleach, keep brushing. How does your water look? Green? Cloudy?

Thanks for the reply!!! Water is mostly clear, maybe a slight green tint. I completed the pool chart this morning. How much bleach should I add each night? I ordered a Taylor test kit yesterday. As soon as it comes in, I will test water, then I want to convert back to salt. How do I do this?

Thank you for filling out the Pool Chart. Yours sounds like a beautiful pool!

I suspect your water has a green tinge as a result of the reaction between the Pristine Blue and the copper in that product. Likewise, the black and mustard algae you mentioned in yur first post could possibly be staining from the copper.

I am out of my depth (no pun intended) when it comes to dealing with metals in the water or converting a pool from Pristine Blue to chlorine and I will make Pooldoc aware of your situation so that he can take a look at it. In the meantime, here are a couple of links to older threads discussing this issue.

http://www.poolforum.com/pf2/showthr...ristine%20blue, and
http://www.poolforum.com/pf2/showthr...-amp-More-quot

Here is an additional link for you, about converting from Pristine Blue to chlorine: http://www.poolforum.com/pf2/showthr...ue-to-Chlorine .

Large amounts of bleach may NOT be your friend just yet. I've contacted Ben for assistance.

Thanks! When I tried to access the links you provided, a pop-up appears and says I am not authorized.

Software issue. It will go away once you have full membership status. Please copy the link(s) and then paste them into the menu bar in a new browser window or tab, that should work.

Your membership is upgraded; you can follow links now.

But . . . it's not clear to me what your priorities are. Three possibilities seem to be:
1. Eradicating algae
2. Getting the pool clear and usable again.
3. Converting back to salt.

If you want to eradicate black algae, and your pool is really truly covered with algae . . . you probably DO need to drain, pressure wash, and then bleach wash.

If you want to get the pool back to clear and usable . . . that will take awhile, quite a bit of chemistry & $$'s, and a lot of brushing.

If you want to get back to salt RIGHT NOW, I'd say that's not very practical.

Ahh, you seem to have it down correctly! My priorities are, in the order you listed, first to eradicate algae, then convert to salt. The pool water is clear, but the algae is really taking over. The water readings have been fine, so the pool has been usable, but the algae is GROSS!

++++++++++++++++++++++++++++++++++++++++++++++++

So, in light of my priorities, your recommendation would be to drain, pressure wash, and then bleach wash? I am so tired of scrubbing. Is this something I can do myself relatively easily or should I hire out?


EDIT by Moderator: 2 posts in the queue were combined.

Okay, I have drained the pool to below the level of the light fixtures, as I can see algae creeping from behind them. I plan to take them out tonight and bleach and scrub behind them before replacing. The bleach in the pool seems to be working, as long as I keep scrubbing. I'm not afraid of hard labor, but this is ridiculous- not to mention the temp and humidity in southern Louisiana right now. I think it will be easier to empty completely and pressure wash. Is there a specific type of bleach "solution" I should use to bleach wash?

Your membership is upgraded now.

1. Eradicating black algae may, or may not be possible. Often it's gotten down into the concrete in places you can't reach. Once you have black algae, you'll always have to be on guard. The only way I know to surely eradicate it is to refinish, with either new plaster or epoxy paint.

+ First step: pressure wash the pool, but NOT with so much pressure you damage your pool.

+ Next, scrub with TSP, and then rinse and remove.

+ Finally, wash down with FULL strength 6% household bleach. Expect that your clothes will be damaged; but wear gloves, rubber boots and glasses. Be VERY careful to make sure there's nothing in the pool -- bleach can create dangerous fumes with many chemicals. A little left over TSP won't hurt, but get out of the pool immediately if you start smelling fumes. I'd do the sides and shallow area first, and then arrange a ventilation fan blowing into the deep end, just to be safe. Have someone watching you -- someone who's strong enough to hold their breath and drag you out! -- while you work the deep end.

Each time bleach gets on you, it strips a top layer of skin. The first few times, that's not a problem. But it can become one. So, don't let that happen while you're working with bleach.

I am not familiar with this stuff- what is TSP?

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Sorry-should've googled before asking- trisodium phosphate!

[ posts combined by moderator ]

Thanks, PoolDoc! I am gonna start the process tomorrow. My test kit should be in this evening. Hopefully by tomorrow night I can start refilling. I will post again then to ask about what to add- i'm sure i'll need calcium cuz i have plaster, and will need to know how much salt to start with! I finally feel like i see a light at the end of the tunnel!

good!