Stupid Algae!

h2o

Well-known member
Jun 30, 2008
68
Houston, TX
I have been fighting algae in my pool since I bought this house two years ago. I keep my chlorine levels in check and shock the shinola out of the pool, but the algae always comes back. I suspect the culprit is the fact that my pool surface is very pourous and in need of replastering. Because of this, I'm not sure any amount of brushing will ever really get all of it.

Considering that I just purchased the house two years ago and had a new baby last year, having the pool redone is just not on the immediate horizon financially. With that said, is there a recommended product that I can add to help control the algae...preferably something that won't throw the chemical balance too far off kilter?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,406
San Dimas, CA (LA County)
h2o said:
I have been fighting algae in my pool since I bought this house two years ago. I keep my chlorine levels in check and shock the shinola out of the pool, but the algae always comes back. I suspect the culprit is the fact that my pool surface is very pourous and in need of replastering. Because of this, I'm not sure any amount of brushing will ever really get all of it.
When you shock the shinola out of it, is it a one-time blast or do you keep it up for several days? Do you use stabilized pucks to chlorinate? They can raise CYA so high that normal FC isn't enough.

Think of algae as yeast. If even a tiny bit remains, it will double, then that will double, and so on until in no time you have as much as you had originally. Even if you keep the FC at maintenance level, you're not killing it as fast as it reproduces. It can hide in behind the light, in little crevasses by the skimmers, underneath pool ladder steps, in the pipe to your booster, even on the underside of your cover.

My only advice is to carefully read How to Shock your Pool. A proper test kit will be required to fix the problem once and for all. Test strips or relying on the pool store won't cut it.
 

Beez

LifeTime Supporter
May 19, 2009
785
Dallas, TX
Just to expand on Richard's advice, the good news is that the problem is not your pool surface. As Richard pointed out, you can fix it once and for all in a matter of days but it will require a reliable test kit and a little patience. :goodjob:
 

h2o

Well-known member
Jun 30, 2008
68
Houston, TX
When I shock, I maintain shock level for several days brushing every day until the FC level falls less tham 1ppm overnight. No matter...after a couple of weeks I will start to see a light algae bloom on the sides of the pool. I spend as much on bleach as I did on pool store chemicals bacause I am always fighting algae blooms. Another key element is that my pool will easily reach temps os 94° - 96° in the summer.

I primarily use bleach as my source of chorine, although I use pucks from time to time as well to maintain CYA levels between 40-50ppm. I also find that I frequently need to add calcium chloride and baking soda to keep CH and TA levels up.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,963
SouthWest Alabama
Sounds to me like you're not maintaining a high enough FC for your CYA level. If you know you're prone to getting algae why wouldn't you keep your FC a little higher?

What do you normally run your FC at?
 

Beez

LifeTime Supporter
May 19, 2009
785
Dallas, TX
h2o said:
When I shock, I maintain shock level for several days brushing every day until the FC level falls less tham 1ppm overnight. No matter...after a couple of weeks I will start to see a light algae bloom on the sides of the pool. I spend as much on bleach as I did on pool store chemicals bacause I am always fighting algae blooms. Another key element is that my pool will easily reach temps os 94° - 96° in the summer.

I primarily use bleach as my source of chorine, although I use pucks from time to time as well to maintain CYA levels between 40-50ppm. I also find that I frequently need to add calcium chloride and baking soda to keep CH and TA levels up.
Sorry! I'm not sure why I thought you were a new user, but that's why I gave my advice. As for your algae problem, I can't shed any further insight because the FC/CYA chart has kept my pool algae free since beginning BBB. I'm also in Texas so I have a smokin hot pool as well, and furthermore at around 30 years old, my plaster is also rough/porous. Your filter/circulation is working properly?
 

h2o

Well-known member
Jun 30, 2008
68
Houston, TX
Bama Rambler said:
Sounds to me like you're not maintaining a high enough FC for your CYA level. If you know you're prone to getting algae why wouldn't you keep your FC a little higher?

What do you normally run your FC at?
At the target CYA level of 40, i try to keep FC between 4 and 5...pretty much dead in the middle of the target range. Obviously, if CYA levels increase, so does my target FC level.

My filter went down over the weekend due to holes in a couple of grids and I was blwing DE all over the pool. I replaced the grids and cleaned everything out real well so I figure now is a good time to figure this algae issue out. Once I got the filter back up and running, I tested the water and my TA and CH levels were low. I added 10 lbs of baking soda and 10 lbs of calcium chloride.

Here are my test numbers from yesterday.

FC - 15
CC - 0
TC - 15
pH - 7.7
TA - 110
CH - 250
CYA - 50
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
I'd suggest running with higher FC min - shocking the pool like you have been doing then - a 24 hour Mustard Algae shock, treating all toys, floats etc. scrubbing by ladders, steps etc., and then running with the MA min for a few weeks - see if that does the trick.

Refer to this chart for the yellow/mustard levels I'm talking about.
http://www.troublefreepool.com/chlorine-cya-chart-t2346.html Not saying you have mustard algae but perhaps something is going on and a higher level would take care of the issue?
 
Thread starter Other Threads of Interest Forum Replies Date
D Algae - Prevention and Treatment 1
T Algae - Prevention and Treatment 5
C Above Ground Pools 3

Other Threads of Interest