Help Needed: Persistent Green Hot Tub Despite High Chlorine Levels

[codyfair]

Hi everyone,

I'm somewhat new to pool chemistry, but I'm struggling with my detached hot tub. My pool is great, and I can keep it in the proper ranges using the Taylor kit. However, my hot tub is always green.

Everywhere I look, it says this is due to algae and a lack of chlorine, but my free chlorine level is currently 4.5 and has been for over a week. I haven't added any chlorine in 10 days, and it still reads as high.

My pH level is 8, and my TA level is 240. I am working on getting those to proper levels. Could these be the cause of the green water?

Any help or advice anyone can give me would be great. My main confusion is why, after testing the water for 10 days in a row, my chlorine level is over 4 when I haven't added any in 10 days, and my water just keeps getting greener.

Oh, and one more thing. On the Taylor test, when doing the FC test, I get the 10mm of water from pink to clear in 9 drops, but after leaving it for 30 seconds, it starts to turn back to pink. My pool doesn't do this—why would my hot tub?

Thank you!

 

[PoolStored]

Ignore the clear going to pink.

Where do you get your fill water? Are you on a well?

Post a picture of the water.

 

[codyfair]

Ignore the clear going to pink.

Where do you get your fill water? Are you on a well?

Post a picture of the water.

What do you mean by Ignore clear going to pink? Are you saying the Taylor kit instructions are incorrect? I put some algae stuff in it last night and it’s not so bad looking today but still don’t know how much chlorine to add especially if I am to ignore counting the drops until clear. Here is pic

 

[PoolStored]

What do you mean by Ignore clear going to pink? Are you saying the Taylor kit instructions are incorrect?

but after leaving it for 30 seconds, it starts to turn back to pink.

Any help or advice anyone can give me would be great. My main confusion is why, after testing the water for 10 days in a row, my chlorine level is over 4 when I haven't added any in 10 days, and my water just keeps getting greener.

What test kit do you have and how old are the reagents?
When was the last time you drained and cleaned?
Do you use well water?

 

[codyfair]

What test kit do you have and how old are the reagents?
When was the last time you drained and cleaned?
Do you use well water?

As I mentioned I have the Taylor kit (K-2006C). It is new. Hot tub is city water filled. Filled 3 months ago which is my usual cycle

 

[PoolStored]

What is your CYA?

 

[codyfair]

Well it’s off the charts because I done use any “sun block” since my tub is covered accept when we are in it. So when the test tube is full to the top with formula you can see the dot clearly.

 

[PoolStored]

If the tube is full and you can still see the dot, that means you don't have any CYA. Without CYA a tub is VERY Harsh. You always want some CYA.

How old are the reagents?
How are you chlorinating?

 

[codyfair]

I assume all the reagents in the new Taylor kit are new so I would say a month or so old. I am using liquid chlorine. Good to know about the CYA. Hard to find good advice. The pool store in my area said I didn't need that.

When you say "Harsh" what does that mean when describing a hot tub? Does it mean hard to balance?

 

[PoolStored]

Harsh means it will be harsh on your skin and clothing.

First, I would read this guide:

Spa & Hot Tub Maintenance A Basic Guide

Hot Tub Maintenance can be done easy with a few tricks. Hot tub chemicals, rashes, and schedules are all covered in this easy to grasp article.

www.troublefreepool.com

@Mdragger88 Thoughts? I'd say SLAM, but it is holding chlorine, and muni water, green getting more green.

Do you have pool math?

 

[codyfair]

Harsh means it will be harsh on your skin and clothing.

First, I would read this guide:

Spa & Hot Tub Maintenance A Basic Guide

Hot Tub Maintenance can be done easy with a few tricks. Hot tub chemicals, rashes, and schedules are all covered in this easy to grasp article.

www.troublefreepool.com

@Mdragger88 Thoughts? I'd say SLAM, but it is holding chlorine, and muni water, green getting more green.

Do you have pool math?

I do. I’ve been using the app on my pool and it’s been going great. I’m just thinking maybe it’s best if I drain the hot tub and start over rather than doing the slam process? It’s probably close to three months and ready to swap out the water anyway.

 

[PoolStored]

I concur. Don't forget Ahhsome purge...

Ahh-Some Questions for First Purge

Hello, I know you all are probably getting sick of me, so THANK YOU to everyone who is taking the time to answer my endless questions! I purchased ahh-some before my spa even arrived haha. I've already disclosed in a previous post, I got too excited to get in my new spa and I didn't purge. :(...

www.troublefreepool.com

 

[codyfair]

Just circling back to the start of our conversation. What did you mean by "ignore the clear to pink?" How else do I measure my free closing level?

 

[PoolStored]

Oh, and one more thing. On the Taylor test, when doing the FC test, I get the 10mm of water from pink to clear in 9 drops, but after leaving it for 30 seconds, it starts to turn back to pink.

What did you mean by "ignore the clear to pink?"

Ignore the "but leaving it for 30 seconds, it turns pink." part. Once the FC test goes from pink to clear, you are done. It is normal, if you let it sit for 30 seconds, to go back to pink. Ignore it. When you are done, pour it out and clean the vial, OR move on to the CC test immediately. Don't wait to add the R-0003 for the CC test.

 

[codyfair]

Ignore the "but leaving it for 30 seconds, it turns pink." part. Once the FC test goes from pink to clear, you are done. It is normal, if you let it sit for 30 seconds to go back to pink. Ignore it. When you are done, pour it out and clean the vial, OR move on to the CC test immediately. Don't wait to add the R-0003 for the CC test.

Ok great! And thank you for all your help