I messed it up, what now?

[zboy]

We have had an above ground pool on our backyard for the kids for a few years now. I always drain the pool after the summer and refill it around May. I could always get through the season by using the 3'' chlorine tablets + algae guard + liquid chlorine. This year I did as usual but about 1.5 weeks ago my pool just suddenly turned green and if I don't touch it I have dead (I assume) algae settling to the bottom but if I brush it a bit it turns the water green and you can see only about a foot down and all murky after. I upgraded the original cartridge filter to an Intex sand filter and has been running for 3 days now continuously but does not seem to make any difference. I checked the water using my kit (HTH strips) and all within the ideal range other than the FC is 10+ and the CYA is ~100. I am very frustrated and about to cut that piece of junk into pieces and throw it out to the trash but may give it another shot:

1. Should I just drain the whole thing and start it over and use that 3'' tablets very carefully, checking the CYA every 2 days to make sure I don't pass 60-70 (South Texas, water temp is 90+)? It costs about $50 to completely refill the pool but it takes about 3 days .
2. Should I try a partial drain (maybe 30%) use some some kind of algaecide to try to kill of the algae? The algae already appears to be dead, it does not stick to anything just settles to the bottom. Will the sand filter filter it out eventually?

They should really put a warning label on those 3'' chlorine tables to stop using after a while. The instructions are very misleading, "treats up to 10k gallons for a week" and "shock'n'swim", shock it once a week and all gonna be fine. I spent several hours of researching all over the web and now I have a better understanding of why my pool got all messed up.

Any suggestion is welcome, at the moment I have no better idea other than completely drain the pool over the weekend start it over .

 

[Texas Splash]

Welcome to TFP! You algae situation can be fixed without draining (perhaps), but to know that we need to know a few very important chemical readings. So here's what you should do:
- The proper test kit (i.e. TF-100 – link below) is the foundation of your pool care. Why this kit? We've learned through personal experience that you cannot reply on pool store testing, test strips, or simple over-the-counter kits. They simply do not read Free Chlorine (FC) or Cyanuric Acid (CYA) levels accurately or to the high levels we need. If you do not have a TF-100 or Taylor K2006 test kit, it should be your #1 priority.
- Armed with the proper test kit, you can then "SLAM" your pool (link below).

Again, those pool products (tablets, pucks, algaecides, etc) are some of the worse products you can use, but pool stores never tell you that. That's how they make their $$.

Get the right test kit, post numbers of your own back here, and we'll help you get it clear again. Welcome!

- - - Updated - - -

I mentioned ""perhaps" drain because if your CYA level is really high, the only way to reduce it is by a drain or partial drain. We'll know more once you get the proper kit to test it.

 

[DaninFLA]

I will second getting one of the test kits. how much is water in Texas? if its cheap and you are not on a well, maybe doing a drain and refill might be cheaper than going thru a full SLAM. 7,000 gallons isn't too bad. I wouldn't drain 100%, would leave a few inches in the bottom so your liner doesn't shift. either way, you are going to need a test kit, bleach/chlorine and patience!

get the test kit ordered asap. I recommend the TF-100, best value and will last longer.

if you have any algaecide, pucks, etc fromt he pool store, return them for a refund and use that money for the test kit.

EDIT - I see you said it only costs $50 to refill to pool. in that case, I would do that. you would probably spend that on bleach, but spend a week probably SLAMing. odds are your CYA is going to be high and a partial drain will be needed either way. I would wiat for the test kit, test and post results and then go from there. but for $50 I would probably do that and get anything bad in there gone and do a fresh restart. have you ever added algaecides, etc? if so, they are in there still and would be good to remove