Yellow algae?

[TredH20]

Hello everyone -

New to posting to the site - but have been reading the tips for a while now here and over at pool forums, where i think everyone migrated from. Anywho...I use the BBB method for maintaining my pool. Started at the beginning of last season and havent looked back. Upon opening my pool this year (mid May) I found the pool to be crystal clear. I have something causing a yellowing on my pool liner, mostly in the deep end. I was able to brush some of it off - but there are large patches that I am not able to brush up. I dont know if it was an algae that discolored the liner - or it is just one tough algae that wont let go. The rest of the pool is crystal clear it is just these sections on the bottom that are causing me trouble. Does anyone know if this could be caused by yellow algae (i say yellow - because it's definitely not green) Some stats on the pool water:

FC: runs between 5-10 ppm, shocking to bring it up 20ppm
pH: 7.2 -7.4
CYA: 60 ppm
Alk: 110 ppm

Will a commercial algaecide work to clear this up? Could this possibly be just discoloration of the pool liner (it's not too old - only about 5 years old). Any helps you could provide would be fantastic.

 

[frustratedpoolmom]

Does it look like this? You describe a prolonged problem I have in my liner.....

new-numbers-am-i-doing-something-wrong-t631.html

scroll down to the pic of the bottom of my pool....

I determined overtime that my stain is not a "live" algea issue because my FC loss is normal and holds overnight. It does fade at shock level, but always returns when I drop to normal levels. I brush and brush and that doesn't seem to make a difference. I was told by a pool store employee 3 years ago that it was "black algae" after he looked at the pics...but the stains are definetly Yellow....

 

[TredH20]

Yes - this looks similar. Not quite as dark as what is in your photo (but that could just be the photo and the angle taken) - it's just an offwhitish yellowish stain in certain sections. So have you been able to remedy the problem with any of the algaecides? The thing that gets me is that i was able to brush some of this away at the beginning of the season - you can see the brush trail through portions of it. But the stuff that remains - won't budge. I lose 1-2 ppm of FC a day lately - has been VERY sunny outside and the pool is in the sun for at least 10 hours a day. So I dont think that I am losing very much to algae. My CC is 0 ppm.

 

[frustratedpoolmom]

Algaecide only prevents algae, it doesn't kill it.

a 2ppm chlorine loss with a 60ppm CYA level seems high. But no cc? hmmmmm....

If it were 1ppm I wouldn't question it, and the fact that you brushed thru part of it.... you may have a residual stain of where it was when it was killed? IDK.

Maybe try a three day shock level treatment, see if they fade, keep brushing the stains and see if they return. Also if you have any pucks you can put one on a sock and let it sit and see if it fades and/or returns when the level drops.

Like I said, mine always return in warmer weather and normal chlorine levels, fades when I shock. My clorine drop per day is about 1ppm, my CYA is in the 50 range and I don't think this is a normal kind of algea. Had it for 4 seasons now... it seems to be worse when the weather is warm and the pool temp goes up. Someone also told me its a kind of mold under my liner....

My pool gets full sun, all day.

It looks icky. I raise my chlorine pretty high before parties....I'm so ashamed...LOL

 

[frustratedpoolmom]

That pic my chlorine was very low and my water temp was almost 90....it's not normally that dark....

 

[JasonLion]

Try placing a trichlor puck on one of the stained areas for 30 seconds and see if that makes any difference. Algae sometimes leaves behind organic stains, which high levels of chlorine can clear up. If the trichlor works you can get the entire stain by holding the pool at shock level for a couple of days.

 

[TredH20]

I'll give the suggestions a shot. I don't know if I have any trichlor pucks left - i may have some of the faster dissolving pucks (dichlor, i believe?). If I do see an improvement with applying a puck - i will most likely wait until Monday to hit with the shock. Dont want to lose any swimming time this weekend!