Green Algae

[poolesq123]

Hi All,

We are new to having a pool and are definitely experiencing growing pains. We have an inground pool. Pump is Hayward Superpump and filter is Hayward S 200 Series. After some technical difficulties, everything is up and running. However, now the pool is green (see photo below). We thought there was some dirt in the bottom of the pool, so we ran the polaris, but that made the water much cloudier and murkier. Pool guys came yesterday, put in a bottle of shock and algacide, noted that the "water is green," but did not do much else. Our TF-100 kit is in the mail (due to arrive tomorrow) and right now all we have is test strips. Chlorine was very low so we poured in a big bottle of clorox bleach last night as well. Any suggestions are much appreciated (if anyone is in Long Island and can help out in person, that would be incredibly helpful too). We are hoping to have the pool ready this weekend, though obviously the long-term condition of the pool is most important. Please let me know of any suggestions. Thanks.

D

 

[JVTrain]

You're in the market for a SLAM procedure as soon as you get your test kit. Until then, add up to a gallon of bleach per day and run the pump as much as you can under supervision in case filter pressure rises rapidly. Backwash the filter when it rises 25% above the "clean" pressure. Clean pressure is the pressure immediately after backwashing, rinsing then starting up the pump on filter again. Stirring things up with the cleaner and brushing is a very good thing to be doing as it loosens algae from where it's attached to surfaces and allows your filter to get the gunk out.

Update your signature with your pool, testing and equipment details as other users have and adding a state to your location helps. Good work on getting the TF-100 ordered. You have the proper tools with that and reading through some Pool School and your pool will be clear soon. By the weekend... maybe not but long term for sure.

 

[poolesq123]

Hi,

Thanks. I will add the tag. For reference, the pool is inground and irregularly shaped (kind of like a figure 8), about 18x32 with an average depth of 4.75 feet. In any event, the TF-100 kit came and we have started the SLAM process. Our baseline readings were 3.5 of Chlroine and 40 of CYA. The indication was to do a Shock16 (which equated to roughly 3 gallons of bleach I believe). We added three gallons of bleach yesterday, have been scrubbing the pool religiously and the coloring is much better (see below). Pool is still murky and Chlorine levels are now at 8. What other steps should we follow to complete the process? I don't have the other chemical levels on hand (but could test as needed). Thanks in advance.

D

 

[Texas Splash]

Keep that FC up!! That's critical! If your SLAM FC level is 16, keep it there 24/7 with the pump running. Double-check anything in the pool (ladder, lights, etc) for hiding spots of algae. MAINTIAN that FC and you'll do fine, but don't let the FC drop.

 

[poolesq123]

Thanks! We are still very new at this and a little confused. This morning, our FC was at 8, up from 3.5 pre-SLAM last night. Should we add more bleach to get the FC even higher? I thought the target was 5 FC. Should we shoot for elevated levels of FC at least until the issue is completely resolved? If so, at what point do we stop (and when is it safe to swim again)? Thanks again.

D

 

[Texas Splash]

Yes, definitely keep the FC up. Refer to the Pool School - Chlorine / CYA Chart, then look for your current CYA. For example: If your CYA was 40, then your FC would need to be at 16 at all times to effectively maintain that SLAM and eliminate the algae. You can go a point or two higher as well as "insurance", especially if you're going to be away form the house for a bit. Don't forget to sweep and keep the water moving to prevent algae from settling. If you have any more questions, just let us know.

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And remember also, you must maintain that SLAM FC level until:
1. Water is clear
2. You do not lose any more than 1ppm of FC overnight (that's the OCLT)
3. CC (Combined Chlorine) is <.5

 

[poolesq123]

Thanks so much! Very helpful. Will spend some more time with the Pool School Chart to fix this.

Have a good weekend.
D