crystal clear water but black algae keeps returning

[tavtel]

So my water is so clear in my Intex above ground pool with a vinyl, no porous liner, it looks drinkable. This was after battling mustard algae by super shocking it, then brushing and vacuuming to waste. I added a clarifier with phosphate remover and a Pool Rx copper ionizer. Water was absolutely perfect for 3 days (accept for mosquitos that my skimmer battled with constantly). Then black algae started to gather on the floor. Vacuumed again and added more shock. Added baking soda. The next day added more clarifier. Tested with HTH test strips, which read super high chlorine and high Ph. Took sample to Leslies whose tests were complete different results and they prescribed another $300 worth of chemicals including alkalinity up, more shock, an algae remover, an algae preventative and more salt. My pool runs 24/7. Always has. I am spending more in chemicals than the 17,000 gallon pool itself.
Please help!

 

[mknauss]

Welcome to the forum!
It is pretty much impossible for black algae (cyanobacteria) to take root on a vinyl liner.
You need to review Pool School linked below. TFPC uses accurate testing by the home owner using a proper test kit to make appropriate chemical additions based on that testing.
I suggest you read through Pool Care Basics - Trouble Free Pool and even look at a few of our videos TFP-TV - Trouble Free Pool

 

[VinnyinNJ]

Welcome to TFP!

The first thing you should probably get is a good test kit, take look either here: TFtestkits.net or get a Taylor K-2006C. You mentioned salt, you're going to need a salt testing kit as well if you get a kit that can't test salt. Spending the money on a good test kit will save you money in the long run. mknauss linked to great information resources and you'll gain some great info. And the people here are willing to you get through this.

Try to stay out of the pool store as you go through the TFP way pool water is handled.

 

[mike4088]

Ph readings are not accurate with fc above 10ppm, there is a workaround I've found works by cutting the sample in half with distilled water. Works pretty good. Without a good test kit you won't be able to accurately measure fc at least levels above 15ppm. The pool store computer will tell the reps what it is but the printout only shows up to 15ppm.

I like leslies, I use their testing to confirm my own work. Recognize their value to your work and don't let them sell you a bunch of stuff that you don't need. Also try not to rely on their water tests, use them to gauge how accurate your tests are. Experience will guide you, you'll know what's what and what you should see when adding chemicals.

Just know this, I have yet to see a rep at leslies not sell a customer whatever they want to buy or whatever their computer tells them to recommend. They don't feel ashamed or embarrassed or anything selling people stuff they KNOW won't help them.

I used a clarifier once, nearly two years later there's still a cloud of it near my pool light. Nothing will get rid of it, the Crud actually attaches to the pool walls when I drain water. It's built up in my returns and everything. Permanently annoying me every day I look at it. Word of caution...

 

[Rancho Cost-a-Lotta]

I like leslies, I use their testing to confirm my own...

Also try not to rely on their water tests, use them to gauge how accurate your tests are.

Greetings Mike.

For the record, TFP does not recommend pool store testing. It has been proven time and time again to be inaccurate and inconsistent. Using pool store testing to confirm results from a TFP recommended test kit makes no sense.

Trust your test kit!

 

[mike4088]

Greetings Mike.

For the record, TFP does not recommend pool store testing. It has been proven time and time again to be inaccurate and inconsistent. Using pool store testing to confirm results from a TFP recommended test kit makes no sense.

Trust your test kit!

Yeah, but the test kits have margin of error as well. I find mine useful all the time, but I still like to double check my work.