stumped by Algae and cloudy water

[red_georgia]

So my pool has been crystal clear for a year until about a month ago. Had very heavy rain storms that turned the pool cloudy and was getting Algae growth every couple of days. I shocked the pool twice and was not clearing up. Had been using tabs for a year so determined my CYA level was way over a 100 so I swapped a bunch of water an now have it down to 70 but still getting Algae growth with FC at 10-15. If chlorine drops below 10 I'm getting Algae daily. Filters were cleaned about a month before the rain storms. Rained again last night and now can't see vacuum at bottom of pool. Just tested water (rain has everything a bit off) and here is my numbers:

FC/TC:8
CYA: 70
Alkalinity 70
PH: 8
TDS: 900
Phosphates: 300

Pool store not much help..... focussing on the phosphates of course. Pressure in filters has not risen since I cleaned them. Any suggestions here? I've had the FC up to 15-20 over a week long period and still didn't get water clarity back even running pump for 48hours straight.

 

[mknauss]

Welcome to the forum! :handshake:

I assume your test results are from a pool store. We do not provide chemistry guidance based on pool store tests. You do need to SLAM Process, but that requires having your own proper test kit.

Order a TF100 test kit
The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want.
I also have the SpeedStir. It makes testing much easier.

Please add a signature. Read Pool School - Read This BEFORE You Post
Information in your signature will show up each time you post and it makes advice more accurate as we know what equipment we are dealing with.

I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.

 

[Richard320]

It's pretty obvious that you still have algae. Tough stuff, too. The weaker strains have already been killed off.

What you need now is aSLAM Process You'll need a FAS-DPD chlorine tester, plenty of powder and drops, and lots and lots of bleach. Pull ladders and lights and brush everything else.

Check out the pictures in these threads
Problem Found and Ideas needed
Think I may have found my FC demand issue?
Water problems

 

[red_georgia]

Thanks, those tests are from pool store but I have my own test kit also which is how I initially discovered by CYA was way over 100. I've read those posts but will read again cause clearly i'm missing something. I had chlorine at above 20 for a week and still didn't get water clarity back and am still getting algae growth with chlorine a 8-10. Did I not go high enough for long enough?

 

[mknauss]

SLAM Process. Read the article. Follow [FC/CYA][/FC/CYA]

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Post a full set of test results from your own kit.

 

[red_georgia]

So, reading those posts, even though you go through a shock/SLAM you are saying that any algae still in the pool will continue to grow and perpetuate problem? I thought the chlorine was supposed to kill it and even if some left in some random spot, it would be dead on not be able to grow. How does it grow again after being killed with super chlorination. Next question.... how do you remove the pool lights? I have two..... pool five years old; I'm sure they've never been out.

 

[mknauss]

If you complete the SLAM and pass the three criteria and then maintain the FC at the target level based on your cya it is unlikely algae can come back.

Are your lights coventional with a ring around them? One screw at top?

 

[red_georgia]

Putting signature in now... question on test kits. I have a full kit made by Taylor but it is branded for Leslies Pool Supplies. On the apparatus for testing clorine/PH.... it only gives you a scale up to 5. So I'm basically guessing after that and just using the math on amount of Clorine and gallons in pool. What kit actually gives you accurate measurements on chlorine up to 50 or so?

 

[mknauss]

FAS-DPD. You can order from tftestkits.net.

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Realize you cannot do a SLAM without the FAS-DPD kit.

 

[red_georgia]

Signature below now. The lights have a silver ring around them with holes in them and one screw at top. Remove the screw and light and wire can be pulled up to side of pool and the receptacle cleaned out?

 

[mknauss]

That should work.

 

[Richard320]

Signature below now. The lights have a silver ring around them with holes in them and one screw at top. Remove the screw and light and wire can be pulled up to side of pool and the receptacle cleaned out?

That's how it's supposed to work. Except the screw might not come out all the way. It will probably be caged so you can't drop it into the depths of the pool. Just loosen it and lift things out.

And to answer a previous question, you didn't have FC high enough for your CYA. You killed some algae, but it was the weak stuff.

 

[red_georgia]

Ok...so I ordered the FAS-DPD kit. I guess I'll put in a gallon of chlorine tonight and run the filter to try to manage it until it gets here.

 

[red_georgia]

I also have a Ozone generator on the pool...if it matters. Do those help at all? Should I be ignoring the pool stores fascination with phosphates? I have so far...... don't like the idea of pouring mud into the skimmer and turning the filters chocolate brown.

 

[tim5055]

I also have a Ozone generator on the pool...if it matters. Do those help at all? Should I be ignoring the pool stores fascination with phosphates?

Ozone is one of those things that sounds better when someone is selling you the system than it is in actual use. Does ozone kill bad stuff in the water, yes. But, only if that bad stuff flows thru the pipe that the ozonator is in. Once the ozone hits the bulk pool water it quickly dissipates and leaves no residual sanitizer in the water. Plus, ozone also reduces your free chlorine....

Phosphates? Again, in a perfect world on paper the reduction of phosphates BEFORE you get algae may help keep algae from growing. But, you are past that point. You have algae and reducing phosphates at this point really doesn't help anything. Once the algae is gone you could reduce phosphates, but if you keep the chlorine level correct for the amount of CYA in the water algae can't live - so, no real need for phosphate reduction.

You need chlorine and to SLAM Process the pool.