Combined chlorine keeps returning

[rmill9681]

So..
Went away on vacation for a couple of days. Before leaving, pool was balanced, added some extra chlorine and algaecide just in case. Had been fighting what I thought was pollen collecting on the floor since opening in May.

Came home to a yellow pool with a ton of algae in the floor. Started shocking, added more algaecide, vacuumed to waste, brushed. Repeated multiple times per day. Cya might have been high 50s, so using pool math I added appropriate amount for SLAM. Also added phosphate remover. Hit it with oxidizer later in the week.

6 days later and another dose of algaecide, pool is finally clear (can see the deep end floor clearly). Still see a few small patches of yellow on the floor near the returns. Vacuum them to waste immediately. Assumed the filter can't capture the tiny yellow algae, so used floc one day, clarifier the next. Added some DE to my zeolite filter too.

Kept FC high 16-20 and finally got CC to 0 this morning. FC dropped to 6, so I added a little chlorine to boost.

Checked tonight and FC dropped to 4 and CC now at 0.8.

I've had high FC for almost 8 days now. Gone through many many gallons and bags. What am I missing? All other chemicals are balanced (ph, alkaline, cya dropped to 40s with all the water I had to replace). Been flushing filter regularly as well. Seems as soon as I let fc get tov slightly higher than normal levels, CC starts to run away.

27k gal inground vinyl liner pool. New liner last season.

Replaced zeolite this season

 

[MA5177]

So..
Went away on vacation for a couple of days. Before leaving, pool was balanced, added some extra chlorine and algaecide just in case. Had been fighting what I thought was pollen collecting on the floor since opening in May.

Came home to a yellow pool with a ton of algae in the floor. Started shocking, added more algaecide, vacuumed to waste, brushed. Repeated multiple times per day. Cya might have been high 50s, so using pool math I added appropriate amount for SLAM. Also added phosphate remover. Hit it with oxidizer later in the week.

6 days later and another dose of algaecide, pool is finally clear (can see the deep end floor clearly). Still see a few small patches of yellow on the floor near the returns. Vacuum them to waste immediately. Assumed the filter can't capture the tiny yellow algae, so used floc one day, clarifier the next. Added some DE to my zeolite filter too.

Kept FC high 16-20 and finally got CC to 0 this morning. FC dropped to 6, so I added a little chlorine to boost.

Checked tonight and FC dropped to 4 and CC now at 0.8.

I've had high FC for almost 8 days now. Gone through many many gallons and bags. What am I missing? All other chemicals are balanced (ph, alkaline, cya dropped to 40s with all the water I had to replace). Been flushing filter regularly as well. Seems as soon as I let fc get tov slightly higher than normal levels, CC starts to run away.

27k gal inground vinyl liner pool. New liner last season.

Replaced zeolite this season

Can you post all your numbers and pool temp? You should go Saltwater generator it’s the best way

 

[bertschb]

Welcome to the forum!

How are you testing your water? You won't be able to resolve your algae problem without a good test kit. If you don't have one, check them out here.

You mention CYA "might have been high 50's". If your CYA was 50, you would need to maintain your FC at 20 based on the Chlorine/CYA Chart If your CYA is 60, you'd need your FC at 24! Soooo, if you kept your FC at 16-20, you never reached SLAM levels. BTW, if your CYA really is in the 50-60 range, you should consider exchanging some of your pool water to reduce your CYA to 30. By doing this, you will need less chlorine during the SLAM process.

I would recommend reading about the SLAM process again and follow each step until you've met all the criteria. If you cut corners anywhere, you'll just extend the time you have to deal with the algae.

I would also stay away from adding anything to your pool other than chlorine.

Good luck and keep us posted!

 

[Bperry]

So..
Went away on vacation for a couple of days. Before leaving, pool was balanced, added some extra chlorine and algaecide just in case. Had been fighting what I thought was pollen collecting on the floor since opening in May.

Came home to a yellow pool with a ton of algae in the floor. Started shocking, added more algaecide, vacuumed to waste, brushed. Repeated multiple times per day. Cya might have been high 50s, so using pool math I added appropriate amount for SLAM. Also added phosphate remover. Hit it with oxidizer later in the week.

6 days later and another dose of algaecide, pool is finally clear (can see the deep end floor clearly). Still see a few small patches of yellow on the floor near the returns. Vacuum them to waste immediately. Assumed the filter can't capture the tiny yellow algae, so used floc one day, clarifier the next. Added some DE to my zeolite filter too.

Kept FC high 16-20 and finally got CC to 0 this morning. FC dropped to 6, so I added a little chlorine to boost.

Checked tonight and FC dropped to 4 and CC now at 0.8.

I've had high FC for almost 8 days now. Gone through many many gallons and bags. What am I missing? All other chemicals are balanced (ph, alkaline, cya dropped to 40s with all the water I had to replace). Been flushing filter regularly as well. Seems as soon as I let fc get tov slightly higher than normal levels, CC starts to run away.

27k gal inground vinyl liner pool. New liner last season.

Replaced zeolite this season

Algaecide is only for preventative maintainence and not for an active algae outbreak. For future reference, the floc, clarifier, and algaecide was all unnecessary. All you need to clear algae is liquid chlorine. If you used MPS (non chlorine shock) you can’t measure CC levels accurately until that stuff is gone since it affects the CC test. Just use liquid chlorine next time and follow the SLAM process.

Once it’s clear, follow the FC/CYA chart for your normal chlorine target.

 

[rmill9681]

Thanks everyone. I'm using the k-2006 test kit, but it only has the black dot CYA test, which I think is pretty subjective.

I'll stick to chlorine and stop adding the other Crud.

I'll test tonight and see how it goes

 

[rmill9681]

Update. Been SLAMing. Last night at dusk FC was 16.5. CC was 0

This morning at 7:30 it was 9.5 FC and 0.5CC.

I had some visible algae yesterday morning, which I removed and then backwashed filter.


Nothing remains in the pool (removed ladder, floating chlorine things, etc.)

Pool is crystal clear.

What could be eating so much chlorine?

Alk: 95
Calcium: 190
Ph:7.6

Cya is the weird one. When I started this process two weeks ago it was in the 50s... Tested this week after original post and it was less than 30. So added a little stabilizer and a pound of dilicholor because I didn't want to overdo it. Waiting for more cya testing reagent to arrive

 

[PoolStored]

Update. Been SLAMing. Last night at dusk FC was 16.5. CC was 0

This morning at 7:30 it was 9.5 FC and 0.5CC.

I had some visible algae yesterday morning, which I removed and then backwashed filter.


Nothing remains in the pool (removed ladder, floating chlorine things, etc.)

Pool is crystal clear.

What could be eating so much chlorine?

Algae. Even if you can't see it.

You might re-read this -->SLAM Process

SLAM is a process and takes time to kill everything. I'd recommend that you test and replace FC every 1-2 hours. Slam is done when CC <=.5, OCLT <=1ppm and water is crystal clear, that includes any debris/detritus in the water.

Keep it up, you will get this!

 

[rmill9681]

Basically, do I need to be replacing filter media or looking anywhere else (pipes, flapper) for active algae?

 

[gingrbredman]

Welcome to TFP!

What am I missing?

First things first, it sounds like from the following posts, you may have been going into a PS and listening to their advice.

algaecide just in case

added more algaecide

added phosphate remover

Hit it with oxidizer

used floc one day

clarifier the next

I do understand this, a lot of members show up here wanting to understand what is happening with their pool, so the good news is you are here and heading in the right direction. None of that stuff listed is necessary for a TFP, or for clearing up your water. You already have your own test kit, now you will fight this with a good ole SLAM.

What could be eating so much chlorine?

As already mentioned, and you probably already know it, but it is likely algae, but something organic is eating all that chlorine. Only the sun burning it off, and something organic eating is causing the drop.

 

[gingrbredman]

Basically, do I need to be replacing filter media or looking anywhere else (pipes, flapper) for active algae?

Look at the wier door, any ladders, behind lights, corners, skimmer, these are all hiding spots for the algae. Scrub the areas, and get as much lose as possible.

 

[an1vrsy]

If you have an autofill, take off the cover and look in there, too.

 

[rmill9681]

Thanks. Still battling it. Drops more than two over night. Water still crystal clear. Stuck some filter socks on the outlets to catch anything coming through filter. Seems to have kept stuff from building on the floor.

Put new liner in last season and it's already suffered from bleaching due to the past four weeks of fighting this

 

[mknauss]

Put new liner in last season and it's already suffered from bleaching due to the past four weeks of fighting this

Liners are not bleached when FC is kept at or below SLAM level based on your CYA. Powdered shock can bleach liners if used and not insured they are fully dissolved.

 

[rmill9681]

It's the entire water line so I don't think it's due to powder and I mostly use liquid.

The CYA level started high, then dropped possibly due to backwashing and replacing water and I kept FC high as each day there was still CC

 

[mknauss]

So your FC was above SLAM level? That is not the processes fault, that is an application error.