Live in south Florida and have SWG for in ground pool. It is kept properly balanced using TFP Kiet & Pool Math. Recently the same sort of algae spots mentioned above have developed in pool. If algaecide isn't recommended, what is? Thanks very much.
Algae spots in Pool
- Thread starter Henry M
- Start date
- May 3, 2014
- 58,367
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Can you give us a full set of test results? If you have algae you need to SLAM Process.
Algaecide is not recommended except in specific cases during the closing of pools in the cold north.
Algaecide does not eliminate algae, it can restrict its growth in low FC environments.
Be sure to follow the [FC/CYA][/FC/CYA].
Take care.
Algaecide is not recommended except in specific cases during the closing of pools in the cold north.
Algaecide does not eliminate algae, it can restrict its growth in low FC environments.
Be sure to follow the [FC/CYA][/FC/CYA].
Take care.
Thanks very much for your reply. Actually, I brushed the spots with a stiff, wire algae brush in the afternoon. This morning, the spots are gone. I increased the %age setting on the SWG. Will wait a day or two to see if any further aglae shows. Does this seem like a reasonable course of action?
- May 3, 2014
- 58,367
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Depends. Do you follow the [FC/CYA][/FC/CYA]? Can you provide a full set of test results?
A SLAM Process may still be in order. Just because you cannot see algae does not mean it is not there.
Can you do a Overnight Chlorine Loss Test?
Take care.
A SLAM Process may still be in order. Just because you cannot see algae does not mean it is not there.
Can you do a Overnight Chlorine Loss Test?
Take care.
First I've ever heard of an Overnight Chlorine Test; want to give it a go, but am unsure what FAS-DPD test is. How does that work?
- May 3, 2014
- 58,367
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
The TFPC method of pool care is dependent on being able to accurately test your pool water chemistry. If you do not have one, I suggest you purchase a proper test kit. I have the TF100 from TFTestkits.net. In that kit is the FAS-DPD test for chlorine. It can test accurately to 50ppm FC.
See Pool School - Test Kits Compared Pool School - What is TFPC?
To do an Overnight Chlorine Loss Test you need an accurate test of your CYA and a FAS-DPD test kit for chlorine.
Once you have your new test kit, run all the tests and post them here. Forum members will provide guidance for your next steps.
Take care.
See Pool School - Test Kits Compared Pool School - What is TFPC?
To do an Overnight Chlorine Loss Test you need an accurate test of your CYA and a FAS-DPD test kit for chlorine.
Once you have your new test kit, run all the tests and post them here. Forum members will provide guidance for your next steps.
Take care.
Many thanks for help. I do have the TF100 test kit; it is the one I use all the time. I'm just not familiar with the term FAS-DPD as such, but I understand now. I will begin the Overnight test & post results tomorrow. Thanks, again.
- May 3, 2014
- 58,367
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
OK -- great!
A great place to get a review of all the tests is Pool School - Extended Test Kit Directions
Take care.
A great place to get a review of all the tests is Pool School - Extended Test Kit Directions
Take care.
Did the OCLT following directions. After sundown, readings were: FC: 16.5ppm; CH: 425; TA:120; CYA:65; Salt: 3300. This morning's FC reading remained the same. Since brushing the pool with the wire algae brush (as normal brushing had no effect), and using the Kreepy Krauly, the black spots (which I assumed was algae, but maybe was something else) have not returned in three days time. The FC reading is awfully high. I moved the output %age from 30 to 40, and the FC shot right up. The SWG & cell were recently tested, and all seems to be working as they should, for this seems to be a constant issue. I just can't seem to find the right output %age. Your advice most welcome.
- May 3, 2014
- 58,367
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Good to hear on the OCLT.
I would suggest starting with a FC use of 1.5 ppm per day in your area right now. That will no doubt drop in the next month but a place to start.
Your SWCG can create 1.4 lb of chlorine gas per day. Or 22.4 oz per day. In your size pool, to get 1.5 ppm FC out of your SWCG you need to run it 4 hours per day at 100%. So depending on how long you wish to run your pump, adjust the SWCG % based on that. (If you run your pump 8 hours, set at 50%, etc). Then adjust as necessary to get your FC to the target level based on [FC/CYA][/FC/CYA].
Take care.
I would suggest starting with a FC use of 1.5 ppm per day in your area right now. That will no doubt drop in the next month but a place to start.
Your SWCG can create 1.4 lb of chlorine gas per day. Or 22.4 oz per day. In your size pool, to get 1.5 ppm FC out of your SWCG you need to run it 4 hours per day at 100%. So depending on how long you wish to run your pump, adjust the SWCG % based on that. (If you run your pump 8 hours, set at 50%, etc). Then adjust as necessary to get your FC to the target level based on [FC/CYA][/FC/CYA].
Take care.
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