Black Algae is kicking my butt

[GEEKMEDIC]

Good morning everyone. I have been lurking here and reading for a couple years to fix my pool challenges with great success, but currently my pool is running away from me. The water is clear but black algae rules. My chlorine is getting eaten so fast I can't keep up. As of this morning the test kit gives me the following numbers; Chlorine < .5, Ph 6.8, Alkaline 110, Hardness ~800 (maybe more, but the color change was not so exact), CYA < 100. So I know that my water is really out of whack, and I've already determined to drain the pool and start from scratch this winter. With the temperature over 100 at midnight in AZ I can't do much more at this point. I appreciate any help you guys can give me to get the numbers more into balance and do something with the black algae.

Have a great day.

 

[mpacheco72]

Do you have a good test kit? That's the most important feature. Without it, it's very difficult for any of us on this site to give you much help. I started with black algae this summer and with a good test kit, the help of this board and a lot of elbow grease I probably have one of the prettiest pools in our area.

 

[UnderWaterVanya]

How are you testing? If strips - they are pretty useless for defeating problems. Get a good test kit (see pool school for more info) and more detailed test results.

Without that you're going to have a really rough time fixing this.

 

[Bama Rambler]

Welcome to TFP.

How did you determine that it's black algae?
Given your CH & CYA you need to drain a good bit of water but since you don't want to do that until the winter it's going to be very hard to "fix" that pool.
If you're using a turbidity test for CYA then run the test by mixing half tap water with half pool water and double the result. Let us know what you get.

 

[linen]

Welcome to tfp, GEEKMEDIC

 

[GEEKMEDIC]

I am using one of the recommended kits. It is the HCH kit. I know that is not the cadillac of kits, but I think it is sufficient for this purpose. I am afraid to drain the pool even half way because of the temperature right now. It is over 95 degrees 24 hours a day. I am willing to do pretty much whatever to fix the problem as long as it doesn't crack my plaster.

Thanks

 

[linen]

I know that is not the cadillac of kits, but I think it is sufficient for this purpose.

In general, and especially for your pool investment, it really isn't. You may be able to get by with it, but if you need to shock, you will be shooting in the dark. Also, you will have not clue about CC levels and you will run out of reagents for the tests you do have very quickly. We basically suggest it only for algae free pools that can be easily (and cheaply drained/refilled) and/or to bridge the gap until an appropriate test kit arrives.

If you cya is close to 100, you may want to drain and refill. It would be best to repeat the test with 1/2 pool water 1/2 cya free water (such as tap water), then multiply the results by 2.

 

[GEEKMEDIC]

I see the need for a good test kit, and it will be on order, but HCH was the one I could get my hands on instantly and it gave me some more information to work with as opposed to no information at all. At what temperature point can I drain the pool even half-way? It is my impression that I should not drain it if the ambient temperature is above 70 degrees. Is that incorrect?