Help with algae, cya 50, shock 20 FC ( and I'm losing the battle)

[Paul_Revaitis]

I have a 18' x 48' Intex pool that was bought for us but my parents when we bought our house last year.I just purchased the TF 100 test kit about two weeks ago. I got it because I can never keep the pool clear, either too much algae or too cloudy.

This past week my pool has been green and not getting better. CYA is 50, and my FC was kept at 20-22.
It's been like this for 5 days now and not getting better.
I got frustrated yesterday because the water has been really warm and dumped 1 gallon of bleach in and brushed and brushed. Cleaned filter and brushed again. (Been doing that all week).
Woke up this morning and most of green is gone but very cloudy.
Tested this morning and FC is at 32ppm and cya still at 50.
I know I can use a better filter than the Intex one and I really want to get one. BUT I am getting my bosses pool and deck in about two weeks that has good pump and filter. So no need to get another one.

First shock (losing battle)

CYA 50
FC 20-22
CC 0

Today (most green gone, but cloudy)

CYA 50
FC 32

(Forgot to check CC)

TC ? (no cc)

 

[Patrick_B]

Welcome to TFP!

If you are following procedure and keeping up the FC level and keeping it MAINTAINED as procedure, this is normal. With that filter system, just be aware that it will take much longer, and be much more difficult to clear. Those little cart system are easily overwhelmed trying to clear an Algae Bloom. It takes a while even with a good sand filter system, so you'll need a lot of patience. If you are getting this in two weeks, can you not just go get the filter system now, and begin using it? That's what I would suggest if at all possible.

 

[Paul_Revaitis]

Hey Patrick, thanks for the reply.
My boss is still using his pool till end of month so that won't be an option.

I do know that every time in the past when I added a lot of bleach the pool would clear up.
I guess with this cartridge filter, I need higher FC level.

 

[pabeader]

Please carefully note what Patrick pointed out. SLAM isn't a one time thing. It's a MAINTAIN thing. You have to get the FC up to the proper level and keep it there. You should be testing every hour and adding more chlorine to get back up to the proper FC. Keep that up until the FC stays up between tests. Then you can stretch out the time between tests. Just make sure that you keep the FC at or above the proper level for your CYA. If you can't do it that often, do it as often as you can. Just make sure that the FC doesn't drop below between testing periods.

 

[Paul_Revaitis]

I did exactly that. Did a lot of testing and free chlorine never dropped below 20. I actually had a 1ppm drop over night.
I did a lot of reading on here and was very anal about it with no success. I tested 4 times a day usually.
Maybe my CYA is higher. My eyes are really good, I go till it's too cloudy to see the dot. Looking at it holding it at waste high.

 

[pabeader]

4 times a day is good for when you are almost done. 10 or more is good at the beginning.

 

[Noorm]

After fighting mustard algae for weeks with slamming, and trying to reduce CYA, on the advice of the folks at 1-800-SOS-Pool, I got some Chlorox Xtra Blue Algaecide. Problem solved, algae gone! I was warned about staining but that has not occured. I believe it is important that the copper in the algaecide be chelated to avoid the stains.

 

[Paul_Revaitis]

4 times a day is good for when you are almost done. 10 or more is good at the beginning.

I agree and I would of tested 10times (or as much needed) but my FC never dropped below 20. I hardly seen a drop overnight.
So I tested before work, when I got home, after dinner and before bed.
If it dropped under 20ppm I would of done it more.

Filter has been running 24/7 for 2weeks now.

 

[Paul_Revaitis]

After fighting mustard algae for weeks with slamming, and trying to reduce CYA, on the advice of the folks at 1-800-SOS-Pool, I got some Chlorox Xtra Blue Algaecide. Problem solved, algae gone! I was warned about staining but that has not occured. I believe it is important that the copper in the algaecide be chelated to avoid the stains.

I also put algae side in last night out of frustration.

I am off tomorrow and Saturday so I will keep closer eye on it.

Funny thing is, even though my pool is at 32ppm FC, the chlorine smell is not strong.

I am staring to wonder if my FC test in TF 100 is accurate.

 

[pabeader]

how much water are you using for the test?
FC doesn't cause a smell CC does and since your CC is low you don't have a smell.

Can you post a picture of the stairs or a ladder?

 

[Paul_Revaitis]

I take the ladder out of pool. I didn't want anything to have a place to grow.
I can when I get home though if you want for other purposes.

I fill the (chlorine only) tube to 10 exactly and add a heaping spoon full of the powder. A little over the flush line.

Good to know about the CC, that explains the no smell. Thank you

 

[pabeader]

There was another thread that discussed this. The reason chlorine has a 'smell' that we associate with it, is when you sniff the bottle, your natural fluids cause a reaction that creates CC in your nose.

 

[Paul_Revaitis]

UPDATE:

In the matter of 24 hrs the pool went from green to very cloudy blue. That was from bringing FC up to 32ppm and from 7am to 6pm it dropped to 24.
I brought it back to 32 last night and am gonna let it come down to 20ppm where the shock should be and see what water looks like.
Question,
How accurate is cya at slam level?

 

[pooldv]

The CYA test is not affected by high FC levels.

 

[Paul_Revaitis]

Update : pool yesterday was blue but cloudy. I let the FC drop to normal shock of 20ppm last night and it was clear enough that you could barely see the bottom. I figured I was on a good track decided I might want to start bringing it down. Is it too early yet? I wanted to get the over night drop of ppm and this morning it is at 18.5ppm.
1.5ppm drop overnight. Is it safe to bring down to ideal FC for 50cya?

 

[pabeader]

Not yet. You say you can see bottom but not super clear. You need to be able to tell heads or tails on a quarter in the deepest part. Keep up the good work!!

 

[singingpond]

Ummm... I really don't think reading heads or tails on a quarter in the deep end should be promoted as an end-of-SLAM criterion. Especially for those of us with marginal filtration, it makes sense to go with a more lenient interpretation of "clear" water, as it can take considerable time to get all the dead algae out.

OP has an 18x48 Intex pool with OEM pump/filter; telling him/her to wait for absolutely perfect clarity before ending SLAM is not appropriate guidance. In my opinion, of course.

OP, with overnight drop from 20 to 18.5, I agree that you aren't quite done yet. Did you measure CC in the morning?

 

[Paul_Revaitis]

Yes CC is .5
Pool is back to 20ppm
Cleaned filter and brushed

 

[pooldv]

Elevated FC levels during a SLAM will help to oxidize the dead algae and clear the pool faster with or without marginal filtration. Clear enough to swim and clear enough to stop SLAMing are two different things. I would continue the SLAM until the water is crystal clear and just drop the FC 1-2 ppm below shock level so you can swim-n-slam. 1.5ppm OCLT is also not a pass.

- - - Updated - - -

With CC at .5 also I would continue SLAM.

 

[pabeader]

From the SLAM article:

You are done when:
CC is 0.5 or lower;
You pass an OCLT (ie overnight FC loss test shows a loss of 1.0 ppm or less);
And the water is clear.

From everything I've read, TPC generally, defines clear as passing the quarter test. Anything less would be just like everyone else. At least as I understand it.

Of course, in the end, it's really up to your level of expectation.

- - - Updated - - -

The problem with not being completely clear, is that you don't really know if it's 'dirt' or algae that's causing the cloudiness.