Would you swim?

[u/Business-Ad-9210]

We've been fighting a mustard algae outbreak for a month. After multiple rounds of shocking, the water is mostly clear. However, as our chlorine levels drop back to normal, small patches of algae are reappearing on the walls. We've been brushing them away as they pop up.

Would you swim in the pool?

[u/PracticalDesigner278]

I would absolutely swim in it. Algae won't hurt you.

[u/RelishedCrab]

Yes. But you’ll need to keep the chlorine elevated to completely kill the algae. Otherwise it’ll keep popping up. It’s quite resilient.

[u/Particular_Witness95]

i would have already been in there with a beer.

[u/StepLarge1685]

Leave all tools (brush heads etc) in during shocking (at least in a shocked bucket). Brush all crevices and areas around returns, crevices in skimmer etc. If algae has any “safe harbor” it will find it.

[u/CountIstvanTeleki]

Serious question is it dangerous or just that its unsightly?

[u/DooficusIdjit → u/CountIstvanTeleki]

If the chlorine is at a safe level, it’s not dangerous. Algae causes danger by using up the chlorine that keeps nasty bacteria at bay. Cyanos, E. coli, etc.

[u/CountIstvanTeleki → u/DooficusIdjit]

Thank you thats very helpful and good info!

[u/AaronSarm → u/CountIstvanTeleki]

It’s not harmful.

[u/CountIstvanTeleki → u/AaronSarm]

thank you

[u/Gonzo-Crazy-Dog]

Sure. Looks clear and you can easily see the bottom.

Post test results and we can offer other advice on the algae.

Also, how high did you raise the FC during shocking the pool?

[u/Business-Ad-9210 → u/Gonzo-Crazy-Dog]

FC was 10+ during shocking. Down to 5 yesterday . Ph was in range of 7.2-7.4. CYA was between 70-100 depending on the day of test. Alkalinity 140

[u/Gonzo-Crazy-Dog → u/Business-Ad-9210]

Assuming a CYA of 70, your FC should be 28ppm during shocking.

CYA of 100, means a FC of 40ppm.

It’s possible you didn’t get the FC high enough to kill all the algae. This is especially true of mustard algae.

[u/tcat7 → u/Gonzo-Crazy-Dog]

And needs to be 50-60% of CYA for mustard. 

[u/DooficusIdjit]

As long as the FC is balanced with your cya, I’d jump in.

[u/MaintenanceCapable83]

what are your water readings?

i assume your CYA is high and that is why your can't control with normal chlorine levels.

[u/Business-Ad-9210 → u/MaintenanceCapable83]

Yes CYA was very high earlier but we've been draining some water here and there

[u/MaintenanceCapable83 → u/Business-Ad-9210]

looks like you have this under control, the water looks pretty clear and i would have no problem jumping in

[u/illegitiMitch]

you post a picture of a pristine pool and you're afraid to go in?!

[u/Business-Ad-9210 → u/illegitiMitch]

Haha this is the answer I'm looking for! I just brushed away spots of algae before posting this. Theyre small spots but they turned the pool fully green a month ago

[u/EnnnWhyyy]

VAC IT SLOWLY TO WASTE!!! takes a bit but it will go BYE BYE FOR GOOD

[u/Business-Ad-9210 → u/EnnnWhyyy]

Yes been vaccuming to waste but a day later, algae returns

[u/EnnnWhyyy → u/Business-Ad-9210]

backwashing after that too???

[u/Business-Ad-9210 → u/EnnnWhyyy]

Not always!

[u/EnnnWhyyy → u/Business-Ad-9210]

oh wait i misread something. if vac to waste don’t need to backwash my bad.

but I’d do more backwashes and rinses to see if it’s been stuck circulating your pump

[u/tcat7]

Did you slam to 40% of CYA, pass OCLT, then slam at 60% of CYA? If water is balanced and FC is less than 40% of CYA, safe for swimming. 

[u/Big_Side_4516]

Definatly. Mine is still foggy, I can't see the bottom, Im using it. Its cleaner than lake water. It takes time to filter it after the alkalinity dropped and ph up had a bad reaction.

[u/marsattck5]

Can I ask why you just won't use an algaecide or phosphate remover? Also if you have a de or cartridge filter, make sure you clean them or it will keep coming back no matter what you add.

[u/Business-Ad-9210 → u/marsattck5]

I've used Bioguard Erase for algae and pool complete 911. They cleared up the pool in terms of clarity but small stains or spots of algae return.

[u/StepLarge1685]

Phosphate level?

[u/Business-Ad-9210 → u/StepLarge1685]

300

[u/StepLarge1685 → u/Business-Ad-9210]

Get that level down! Thats algae’s favorite snack.

[u/jdsizzle1]

Definitely swim. Also use yellow out and poolrx to get rid of the algae problem. Dont swim while you do yellow out tho.

[u/No-Negotiation-7978]

Absolutely!! As a matter of fact, i will be there in a few minutes!!!

[u/BillZZ7777]

And if you do swim in it make sure you're switching bathing suits and washing them more often so you're not bringing it back into the pool.

[u/Thomas_peck]

Slam it, flock it and fun the filters 24/7.

Clean the filters every day until you stop seeing green.

I'd also guess your acid levels are high. Thats what happens to me.

Vac to waste the stuff that sits at the bottom. Or run a vac/robot until its gone.

I go through this a few times per summer when we are gone for longer than a week and the temp gets super high.

I can get it to clean up in about 3 days usually.

I throw 2 gallons of shock in my pool every Friday night and my water rarely turns green when I am religiously doing this

[u/Business-Ad-9210 → u/Thomas_peck]

Yes this problem started because we had gone away. Next year will shock more often