Green Algae That Won't Die

Apr 20, 2016
4
Joliet, IL
I have a 24' round above ground pool. The winter cover fell in and there were a ton of leaves in the pool so I decided to open it earlier than normal to get a head start on cleaning it. I removed all the leaves off the bottom. Hooked my pump and filter back up. Checked all my levels and they were as follows:

pH - 7.2
FC - 0
TA - 120
CH - Don't have the test for this one
CYA - 47

I proceeded to add two gallons of liquid shock, 10% chlorine. I ran the pool all day and the chlorine did not change anything even though the free chlorine level was above 10. The test kit I have only goes up to 10ppm. The levels had to be above 10ppm because the test color water was orange when I added the 5 drops of OTO.

So with the advice of a pool guy, I added a four more gallons of shock last night. Still green this morning. Test color again orange so ppm is very high.

I have been cleaning the filter daily and my pump's pressure is really strong. I know chlorine levels have to be above 30ppm, way higher than I have ever had it.

This green will not go away. In fact, it's very bright green.

I run a SWG system and have never had an algae problem ever over the years. First time I have had to deal with something this bad.

I'm starting to think I may have to drain this pool. I can't add anymore chlorine right now because the levels are very high as it stands. When I clean my filter, it is brown dead algae I'm rinsing off the filter. But the green in the pool itself will not budge.

What am I doing wrong?
 
I am scrubbing daily and rinsing the filter twice daily. I got the pump running Monday so it has only been a couple days. The pool was really bad. I'm probably just being impatient but I was hoping to see the water color change a bit by now. So should I just maintain shock levels until it clears and keep scrubbing and rinsing the filter? How many days should I do this until I should worry?
 
Yes, maintain the shock level and keep the filer clean, and brush. I opened on Saturday....it was still pretty dark green when I left for work on Monday. When I got home I could see the bottom, though still a little cloudy. Now it's completely clear. It will also depend how effective your filter is at picking up the algae.
 
Something that would very important to verify is how did you come-up with the CYA of 47? Was this from your own test kit? I will say this though, if that CYA reading is correct, and we round it up to 50m your SLAM/Shock level FC would be 20. An FC of 20 would need to be maintained 24/7 (with pump running), following all the other directions noted on the SLAM page (link below). Patience certainly is key, but all the patience in the word won't help if those tests are estimated or provided by anyone else other than your own test kit (TF-100 link below). Just something to think about. Stick to just the regular bleach though. Generic bleach is fine, just make sure it's plain, none of that splashless or scented stuff. If your SWG is still running, you can give it a break if you want only because your required FC need to be much higher than it probably can produce, but that's up to you.

Definitely make sure you've covered everything listed on the SLAM page and let us know if you still have any questions.
 
Take a picture each day looking down on your steps. Post them up and share them here. THAT will show you the progress. Your eyes cannot see the difference day to day.

It took a while to get like this :( It will take a while and LOTS of bleach to clear it back up. BUT it can be done and will be SO worth is!

Kim
 
After reading around the forum a bit, I can see I need a better test kit. The kit I have right now is a HTH 6 way kit. It has a little tube with a black dot at the bottom that I filled with the test water and cyanuric acid reagent mix until I couldn't see the dot any longer. Was right around 47. Time to buy a better kit so I can get readings on everything. Only had the pool about 5 years and never had to deal with an algae bloom. Think my impatience is getting the better of me. I will order a new kit and in the meantime keep the pump going and chlorine up. Looks like slamming is the way to go. Thanks for all your replies. I will keep you updated on the progress.
 
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