Algae help

[Jo Lewis]

Hi,
I think I have mustard algae. Each day I vacuum my pool and it is clear all day. The next morning there's something that looks like sand and poofs in the water if I brush near it. I was checking with the strips 2x per day and all was well. Each week pool store tested and said everything was balanced. Again, my water is always crystal clear but this algae stuff is there every morning. Now I'm noticing since it became hot that my TC and FC is less than 1 yet my combined is over 3. My CYA is 35. Ph 7.2 to 7.3. Alkalinity 84.
I've tried following the steps to shock but everything I've read says mustard algae is resistant to chlorine. I get the chlorine to well over 10 (a few nights it's been at 20). In the morning, it's back down to 0. So, I can't get 3 days under this SLAM protocol.
My pool is an 18ft AG. Newly installed - 6 weeks. Glass filter media. I use skimmer socks. Backwash weekly. Run it 11am-3pm and 11pm-7am everyday. I've vacuumed to waste almost weekly. Replaced about 1/4 approaching 1/2 of the water.
Any recommendations?

 

[Teald024]

Hello and Welcome to TFP!!

Sorry to hear of your pool woes. It all starts with testing. You need to get a good test kit that can measure pH, FC, CC, TA, CH, and CYA. I recommed the TF-100 from TFTestkits. Don't let sticker shock set in. I've never seen anyone that has regretted getting the kit. Test strips are considered inaccurate here as is pool store testing.
It is highly likely that you do NOT have mustard algae. Your algae issue is due to low chlorine for your CYA. You are about to get cloudy water and then turn green if you don't get chlorine in the water.

You mention the SLAM procedure, but to be honest, you haven't started it yet. You have not raised FC to shock level and definitely have not maintained it at shock level. While doing the SLAM procedure, pump & filter should be running 24/7
Please reread the SLAM Process and follow it exactly. No shortcuts, and you get that morning "dirt" cleared up in no time.

While you are waiting for the test kit to be delivered, you can add a gallon of 6% bleach to your pool. Thats regular bleach from your favorite grocery store. Non-scented, not splashless, not Chlorox brand. And continue to brush daily.
Once you get your kit, run a full set of tests and post them here and we can offer more advice.

pH
FC
CC
TA
CH
CYA.


Lots of abbreviations and these can be read about in ABCs of Pool Water Chemistry

 

[Jo Lewis]

I ordered the kit from amazon. The delivery is somewhere between 8/2 and 8/19. Should I try to slam it in advance?

 

[Jo Lewis]

My initial test results as I got my kit:
FC 9
CC 2.5
TC 11.5
CH 744
TA 260
CYA 100
PH 6.8
CL/BR 5/10
Ph 6.8

Please help me figure out how to clear the haze and get rid of the dusty algae that returns every morning.

 

[Mr Bruce]

You are going to need to do at least a 50% water replacement (CYA 100+) . After that everything Teald024 said.

 

[Teald024]

I ordered the kit from amazon. The delivery is somewhere between 8/2 and 8/19. Should I try to slam it in advance?

Which kit did you order?

My sugestion is to cancel the order from Amazon and get a TF-100 from TFTestkits.net . The time quoted above is too vague. With TFTestkits.net, you might have it by the weekend, If not, by Monday.

 

[frogabog]

Which kit did you order?

My sugestion is to cancel the order from Amazon and get a TF-100 from TFTestkits.net . The time quoted above is too vague. With TFTestkits.net, you might have it by the weekend, If not, by Monday.

I was just going to say that... Amazon's delivery on the TF-100 is ridiculous. TFTestkits ships fast!

 

[Jo Lewis]

I got the TF-100. It came faster than the timeline amazon gave. I did the tests and read the slam protocol and pool math. I feel like I should test cya again. The pool store shows my cya at 30. My strips show 40 and this test was greater than 100.

 

[frogabog]

Dilute your pool water by 50% with tap water. Then run the CYA test from your TF-100 again. Multiply the result by 2.

Your test is the most accurate. Throw the strips out and don't listen to the pool store. You are in charge now.

 

[Jo Lewis]

Ok, I'm going to vacuum to waste and refill.

 

[AimeeH]

The CYA test is the hardest to master. You can pour the solution from the sight tube back and run the same test multiple times. Make sure you are doing it in full sun with your back to the sun. I don't even bother testing on a cloudy day.

 

[Jo Lewis]

Ok, I'm refilling the pool now. I've vacuumed to waste, backwashed and rinsed. I'm going to check cya and start this slam based on my numbers overnight. I'm tired of waking up every morning to the dusty algae and no chlorine.

 

[Jo Lewis]

I can't seem to get the cya down. I'm not sure if I'm testing it correctly with the black dot. Nevertheless, I started the slam as if the cya is correct at 100. I've emptied half of the pool and spent hours refilling it. So I started the slam last night. When I went to bed at midnight I had a FC just over 40. The target is 39. This morning it was 26. I used pool math and added bleach to get it back to 39. Midday check 23. I've added again for 39. Waited 2 hours. Checked 24.
The water is crystal clear. The Cc is 0. But since I didn't pass the overnight, I slid continue with slam, right? The algae has reoccurred all day. I've been brushing and running the vacuum. I clean up a spot, walk around the pool and find a different spot where it has settled. It looks like small patches of sand.

 

[frogabog]

Yes, continue SLAM. Give it a little time, keep brushing. As long as you see algae you've got algae, to be sure. You're doing all the things you should, it just needs to break through. Chances are it'll go cloudy once you really get through to the algae.

Check your pool ladder, steps, lights, etc. Brush or clean with bleach every spot where it could be hiding.

You did another CYA test after draining and refilling? Sounds like your CYA was closer to 200 if that's the case. If you can do another 50% drain, you'll save $ on bleach while you're slamming. Plus, it will help with the algae.

Another thought, if your CYA was really at or above 200, you may not be hitting SLAM FC level even at 39ppm. Once you get the CYA down under 100 you'll have a much clearer idea of your SLAM level.

 

[Teald024]

I agree that it sounds like your CYA was through the roof, 200+ppm. Although you may be reluctant, draining half again and refilling will probably be the best course of action. It'll drop that CYA in half again and help remove some algae. I fear that you may still be higher CYA than you think, The CYA test is not very accurate at those CYA levels.
If it was me, I'd drain leaving 1 foot of water in the shallow end of the pool and refill. You will save chemicals and testing reagents. You should pay attention to the amount of R-0871 reagent you have left so you don't run out. At 70 drops per test, that bottle won't last long.

 

[Jo Lewis]

I'm already at the point where I need to order another bottle of 0871 and it's only been 2 days. The pool is clearer than it has ever been. The CC is 0. And the FC is now at 36. Although slam chart says 39. I've brushed all day and vacuumed. As soon as I put the brush down it appears in another spot. I've brushed the steps and behind the ladder. It's definitely an algae as it poofs when I get the brush close.

 

[frogabog]

Baby steps seem to be working in your favor... I'm curious what your CYA really is (was).

 

[Jo Lewis]

Baby steps seem to be working in your favor... I'm curious what your CYA really is (was).

Well the pool store usually says somewhere between 35-50..At one time I had a package of strips that said it was over 100.. When I ran out of strips, I bought a different pack and that places it in the normal range. But with the TF 100, I've done the test inside, outside and my husband has done it as well and the water gets nowhere close to 100. So we just assumed it was way higher than 100. I dumped half the pool (I am certain my neighbors were wondering why all this water was running into the street). I refilled it over the better part of the day.
This morning my FC is the same as it was last night at 9pm and that's 36. The CC is 0. However, there's now dark brown algae spots and although fewer, there are still new light gray dust patches. I've turned the auto vac on.

 

[Mr Bruce]

The point of the 50% water replacement was to lower your CYA. You need to do another CYA test to see where you now stand.

 

[Jo Lewis]

The point of the 50% water replacement was to lower your CYA. You need to do another CYA test to see where you now stand.

Ok. I did one yesterday and it was still over 100 but I will do another.