Do I have an Algae problem?

[Junta]

Hi Everyone,

I have 27' round above ground pool with a brand new liner. About 4 weeks ago or so I noticed some algae on the bottom. Very light and if you weren't looking right at it you wouldn't see it. I shocked my pool, brushed the pool and vacuumed. Everything seemed okay. A week later, I see the same thing happening again. I brushed and vacuumed and it seems good for a few days but then I see green on the bottom again. My pool water is crystal clear and I did an overnight check of the chlorine and I didn't loose any. What's going on? Do I need to shock again? Or do I need to SLAM my pool? I am in CT and will be shutting my pool down on labor day. If I need to shock or slam can I combine that with my normal pool shutdown?

Here are my last few chemistry readings:

pH : 7.3, 7.2, 7.2, 6.8
FC : 14, 6.5, 7.5, 6.5
CC : 0.5, 0.5, 0.5, 0.1
TA : 90, 90, 90 , 90
CYA: 45-50

Thanks for your help!

 

[kimkats]

How are you getting your test results?

If you are seeing algae you need to SLAM. I would do it before you shut down so you will have an easier opening in the Spring.

I would also think about waiting to shut down when it is below 60.

Kim

 

[jblizzle]

Welcome to TFP!!!

There is never a need to "shock" as you say. If you have a problem, follow the SLAM process, after passing the 3 criteria to stop, then just maintain adequate FC for your CYA according to the FC/CYA Chart

 

[domct203]

Hi Everyone,

I have 27' round above ground pool with a brand new liner. About 4 weeks ago or so I noticed some algae on the bottom. Very light and if you weren't looking right at it you wouldn't see it. I shocked my pool, brushed the pool and vacuumed. Everything seemed okay. A week later, I see the same thing happening again. I brushed and vacuumed and it seems good for a few days but then I see green on the bottom again. My pool water is crystal clear and I did an overnight check of the chlorine and I didn't loose any. What's going on? Do I need to shock again? Or do I need to SLAM my pool? I am in CT and will be shutting my pool down on labor day. If I need to shock or slam can I combine that with my normal pool shutdown?

Here are my last few chemistry readings:

pH : 7.3, 7.2, 7.2, 6.8
FC : 14, 6.5, 7.5, 6.5
CC : 0.5, 0.5, 0.5, 0.1
TA : 90, 90, 90 , 90
CYA: 45-50

Thanks for your help!

Hello neighbor, and welcome to the forum.

As mentioned, it's best to wait until the water remains below 60F to close the pool as FC loss & algae growth will be extremely slow. Also, don't close your pool with algae in it or it will be a major PITA in the spring.

If your FC has been at, or dropped below the recommended minimum for your CYA, that is most likely algae.

To do a proper OCLT you should raise the FC to SLAM level and be sure that the evening test & morning test are at lest 8 hours apart if possible.

How have you been testing & chlorinating your pool?

Please add your pool & test kit details to your signature to help us help you.

Dom

 

[Junta]

My test kit is the TF-100. I have been testing and chlorinating my pool. I think the chlorine did drop down below my min CYA level so that may be it. I figured I jumped on it pretty quick so it wouldn't be an issue but guess I was wrong. I am surprised though as this is the most attention I have ever paid to my pool chemistry and I have algae. Prior years all I would do is check for chlorine and add more if it was low and I never had any problems. Oh well!

But how important is it to wait until the temp is 60 degrees? At my location we are at the edge of the woods and leaves start falling not to long after Labor Day. The maintenance becomes too time consuming to keep it open much longer than that. Plus we don't get any use once the kids go back to school and fall sports start.

Thanks for the help so far. Is my signature sufficient?

Hello neighbor, and welcome to the forum.

As mentioned, it's best to wait until the water remains below 60F to close the pool as FC loss & algae growth will be extremely slow. Also, don't close your pool with algae in it or it will be a major PITA in the spring.

If your FC has been at, or dropped below the recommended minimum for your CYA, that is most likely algae.

To do a proper OCLT you should raise the FC to SLAM level and be sure that the evening test & morning test are at lest 8 hours apart if possible.

How have you been testing & chlorinating your pool?

Please add your pool & test kit details to your signature to help us help you.

Dom

 

[domct203]

My test kit is the TF-100. I have been testing and chlorinating my pool. I think the chlorine did drop down below my min CYA level so that may be it. I figured I jumped on it pretty quick so it wouldn't be an issue but guess I was wrong. I am surprised though as this is the most attention I have ever paid to my pool chemistry and I have algae. Prior years all I would do is check for chlorine and add more if it was low and I never had any problems. Oh well!

But how important is it to wait until the temp is 60 degrees? At my location we are at the edge of the woods and leaves start falling not to long after Labor Day. The maintenance becomes too time consuming to keep it open much longer than that. Plus we don't get any use once the kids go back to school and fall sports start.

Thanks for the help so far. Is my signature sufficient?

If you could add the water depth, or volume in gallons to your signature that would help.

You don't have to wait, but if you close when the water is below 60F there is much less of a chance opening to a green pool in the spring.

Dom

- - - Updated - - -

Do you plan to SLAM before you close?

 

[kimkats]

When you close is up to you! You know what you have to deal with. We just say it is easier water wise to wait to close under 60 degrees BUT if you have those kinds of leaf problems..........do what works for you!

Kim