Newbie with algae (and probably other) problems.

[Emil Wick]

Hi all,

Just ran multiple tests with my new TF-100 kit. (First Time). I've been having an on/off problem with algae--brushing takes it away but it returns rapidly. Daily BASIC TESTING results have consistently given high level for CL and also have had constant high PH. I add muriatic acid 2-4 times per week.
Today's test shows CL low AT .5 and PH at 7.8 I need some help on what to do immediately instead of simply dumping in chlorine.

My Data:
15,000 gal pool, 30y/o, plaster finish.
Variable speed pump.
Current pool temp 77 deg.

CYA 100
FC .5
CC 0
TA 120
CH 750

Any helpful response will be greatly appreciated!
Thank You.

 

[woodyp]

Your cya could be well over 100. Use half pool water/half tap water and multiply the resulting reading times two to start with. I'd prepare to drain and replace a good bit of water. Welcome to the forum.

 

[tado921]

CYA 100

That's a problem. You probably aren't maintaining a high enough FC level to compensate for the high CYA. You should try to reduce the CYA level by doing a partial drain and refill if possible. Look in the Pool School and find the information about the FC/CYA relationship. This will help explain why you should lower CYA. IMO, that is your #1 problem.

 

[Emil Wick]

Thank you for the speedy reply. I did the tap/pool water test and CYA is 120. I live in San Diego County and am loathe to empty the pool because we are in a severe drought situation here. Is there any other possible "fix" for my problem that would allow me to keep the water I have for the time being?

Again, many thanks!

 

[tado921]

According to the chart, with a CYA of 120 you should maintain minimum FC of 7, with a target of 12. However, with CH of 750 you run the risk of calcium scaling at these levels. If you could get your CYA down to 80 or 90 it would help quite a bit, but this requires replacing roughly 1/3 of your water (about 5000 gallons). To hit 12ppm FC, you would add 260 oz. of 8.25% bleach.

Unfortunately there isn't any easier way to reduce CYA.

 

[Tanner M]

Thank you for the speedy reply. I did the tap/pool water test and CYA is 120. I live in San Diego County and am loathe to empty the pool because we are in a severe drought situation here. Is there any other possible "fix" for my problem that would allow me to keep the water I have for the time being?

Again, many thanks!

Water replacement or reverse osmosis are the only two options you have.

 

[Emil Wick]

Thank You much for the suggestions. I will be doing research on this.

 

[Richard320]

Thank You much for the suggestions. I will be doing research on this.

http://poolservicestech.com/ offers reverse osmosis, and you're probably within their service area.