Algacide when closing?

[rigger7]

I've used the BBB method this season and I have looked at how to close a
pool on pool school what I was wondering why algaecide?
Do I have to do this if I'm using the BBB method?

 

[duraleigh]

Do I have to do this if I'm using the BBB method?

No....it's optional. Many folks close by bringing the FC to SLAM value only. Others close by bringing the FC to SLAM value and adding polyquat 60 algaecide as added protection.

There does not seem to be consensus showing a CLEAR advantage by adding algaecide but it's your call.

 

[BoDarville]

The use of a polyquat 60 algaecide is optional when closing a pool. It will provide a little extra insurance against an algae bloom. What is far more important is to not close the pool too early when water temperatures are too warm. Wait until the water temperatures consistently stay in the fifties (Fahrenheit) before closing.

 

[dschribs]

I do BBB and used a quart when I closed my in ground. I mixed it with water in a 5 gallon bucket before pouring it in the pool since it's pretty thick. I figure it's a little extra insurance over the Winter. I used Leslie's Algae Control since it seems like it's similar to polyquat which is highly recommended here. Also raised FC level to SLAM level prior to closing.

 

[chem geek]

To be clear, so long as the chlorine lasts there is no need for the algaecide. The purpose of the Polyquat 60 algaecide is to continue to inhibit algae growth even if the chlorine runs out or gets too low. If you close the pool very cold and open it before it warms up, then you should be able to keep chlorine in it the entire time, depending on how long it is closed. If you've never done a closing like this before, you can use the Polyquat 60 and then measure the chlorine when you close (after dosing and mixing) and when you open to see what kind of loss you can expect and if the chlorine lasts. If it does, then you don't need to use the algaecide in the future. If it doesn't, then you do.