3+ weeks ago, on start up, I drained the pool because of algae. I filled it up, replaced a cracked pump, used a whole bottle of algae remover and filtered it for days but it's still green.
Last weekend I changed the sand and filtered for 2 days but it's still green. THEN it was suggested I use "First Aid" was told it would kill even oil in water in 24 hours....IT DIDN'T!
Now it's just a yucky greyish green! I'm at a loss!! After looking at your website I do see where I may have backwashed too much but initially it was moving some of the dead algae out.
Oh yeah, & I used superfloc. Have a 12' x 18' oval pool in Louisville KY
Thanks for your question Tana
I've been to Louisville a couple of times. Used to live in Owensboro for a couple of years. We'll start from the "whole bottle of algaecide". An algaecide is used for preventative maintenance only. It's not to get rid of nor kill algae already present in the pool.
Whomever told you to use an algaecide to kill already existing algae is mistaken. An algaecide can be used as a backup for a green pool, but this is with a very good chlorine shock. The chlorine will kill the algae and the algaecide is used for a little insurance because the chlorine level will be reduced quickly due to the algae.
I'd like to have your chemical readings. This makes the process much easier. Because you drained the pool 3 weeks ago, I will assume you don't have any CYA in the pool. I have to assume because I don't have your chemical readings. Keep filtering 24/7. This is important because the filter will be doing alot of work. Back wash once per day to get rid of the algae.
Next is to shock the pool with Dichlor chlorine. This is a
stabilized form of chlorine that will not only put chlorine in your pool, but will add CYA to it. Be careful in using Dichlor because your CYA can increase quickly.
For every 10ppm of chlorine added with Dichlor, you'll raise the CYA 9ppm. For a 12 X 18 pool you probably have anywhere from 5000 - 6000 gallons of water.
You'll need 11oz. of Dichlor to reach super chlorination. I would encourage you to go a bit higher, maybe even 1 pound. It's better to go a little over than not hit that mark. Do the shock and night and retest in the morning.
You'll know the shock is working because the algae will turn a white/gray color. Shock the pool again with Dichlor, but remember to test for the CYA as well. Again, only use Dichlor if you have no CYA in the pool. If the CYA is present (between 30 - 50ppm) use regular unstabilized chlorine such as liquid or granular.
I would encourage you to lay off anything else.
High doses of chlorine is the only thing that will get rid of pool algae. That, and filtering and back washing.
Most real pool guys will tell you that shocking and filtering are the best ways to clear up a pool in this circumstance. Once you get the Dichlor and CYA in the pool, you can then switch to either liquid or granular chlorine to daily dose your pool. If you have hard water already, use liquid chlorine.
Test every evening and keep the chlorine level above 10ppm during this process. You don't want to give the algae any chance of coming back.
Filter 24/7 and back wash. Use the above links as much as you can. They have alot of good information on them. It may take more than a couple of days to see any results. The main thing is to be patient and keep on the chlorine.