Doing SLAM on algae

[handyharry]

Will i need to use a flocculant after the slam to clear the dead algae?

 

[woodyp]

Welcome to the forum and NO, we don't recommend it. Just vacuum to filter and backwash or waste.

 

[handyharry]

I am flying blind on algae with the SLAM approach. Can't get a test kit till Thursday. I know, I know, I thought I could handle this without the specific kit. Been to the 2 local pool places yesterday and just a bit ago. Yesterday readings FC 8.22; TC 8.7 CC .48; CYA 52; PH 7.1. I backwashed filter and added PH Up, waited two hours and broadcast two gallons of liquid shock. Current readings today FC 13.89; TC 14.96; CC 1.07; CYA 46; PH 7.4. If I am understanding the CC number correctly, I am still dealing with algae and should add more shock. Pool store says algae is dead at this level and should do flocculant and vacuum to waste. I have been using phosphate levels as a gut feeling that algae was still present and yesterday was the first time into acceptable range. Today the phosphate reading is back to 263. I just want to be done with this problem. I should have followed my gut 6 weeks ago and drained and started fresh.

 

[mknauss]

While waiting on your test kit, add 5ppm FC worth of liquid chlorine each evening to the pool with the pump running.

When you get your test kit, post up the results.

Phosphates do not matter. Do not use Floc.

 

[mknauss]

Have you read SLAM Process? Also FC/CYA Levels, ABCs of Pool Water Chemistry.

 

[handyharry]

I have read the listed items. Gone back and re-read numerous times to try being sure I am understanding everything. My pool is 12,000 gallons. Based on the one day increase from two gallons, I should add roughly 1 gallon to achieve 5 ppm of liquid chlorine??

 

[handyharry]

The CC reading that increased means I DO Still have algae??

 

[mknauss]

One gallon of 10% liquid chlorine will give you just over 8 ppm FC. If you are using 6% bleach, that is 5ppm FC.

You do not have a test kit. So until you have that, it is hard to say what is going on with your pool chemistry. If the pool is green and/or cloudy, you still need to follow the SLAM Process

 

[handyharry]

If I drive about 30 miles I can get a drip test kit (today) that will do total chlorine and combined chlorine. Can I use that and do the math to get the free chlorine reading? And Thanks for your input here.

 

[mknauss]

No. You need a FC test to measure above 10 ppm.

 

[handyharry]

Got my Taylor DPD test kit. I have added 1/2 gallon of 12% chlorine each of the past 2 nights as you suggested. My FC is 5.5 and CC is over .5 (probably .75) after using the less precise .5 method figuring on higher levels. CYA is >.4 I did not previously mention it, but I have a floor cleaning Bot with 2 micron filtration bags and it says algae is present based on collected stuff so I know I have not resolved the issue. What is my next step on a 12,000 gallon pool?

 

[Lemonred34]

Is your CYA test withthe tube and black dot? >.4 doesn’t give much of a result. For the SLAM process to work, you have to know your CYA. For example if your CYA is 50, your SLAM FC target is 20. You will need to add enough liquid chlorine to bring it up to 20 at least 3 times a day, more if able. You will continue to do the slam until you pass all 3 criteria listed.

 

[handyharry]

My CYA is about 45 with the black dot which I find to be a somewhat subjective to interpretation kind of test. I have had tests done at vatious pool places and all were between 40 and 50. I have just completed and passed the free chlorine overnight test. CC is .2 with the more accurate 25ml test and my FC level was 13.5 at 6 AM. I do NOT have clear water YET. Does that mean I continue with FC at SLAM levels? Will water become clear with such high chlorine levels??

 

[handyharry]

I had to visit another pool supply store for more titrating solution to continue testing such high chlorine levels to add to confusion about what needs to be done to have success. I really wish the kits came with the larger bottles of solution for this method. It was difficult to leave with only the solution I went there for to complete this process. What is the longest treatment time others here have experienced before seeing clear water after passing the CC test and the overnight FC test?

 

[Fast7]

I think you got K-2006, not K-2006(c). It is basically a smaller copy, so much less reagent.
During SLAM, do 10 ml sample instead of 25 ml.
Back to your SLAM question, you can't move to OCLT unless water is clear.

 

[handyharry]

OK. So want to go really crazy?? I really don't know what to believe about any testing now. I did a FC test at about midnight last night with the smaller reagent from the Taylor kit and got 18.5 FC 37 drops. Got a fresh sample not long ago and used the new Taylor 2 oz. bottle from the pool store which I purchased yesterday and got a result of 21 FC - 42 drops. Nothing had been added to the pool, so I tested the same water sample with the reagent from the kit and got a result of 17 FC - 34 drops which is what might be expected for a reading. I am probably gonna have to contact Taylor for input, but I compared the drop size on a piece of plastic laying flat on the countertop AND the 2 oz. bottle I just got has a bigger drop size ( both held Vertical) than the one that came in the kit. It took more drops of a bigger drop size to complete the test. Very confused. Water will NEVER be clear.

 

[Wobblerlorri]

Check the expiry dates on the bottles. I bet the new bottle has the latest date, and is fresher.