White Slimy Film On The Bottom Of Pool

by Nancy
(Big Stone Gap, VA)

We have an above ground pool that we have just opened for the summer.

Upon removing the cover, the water was crystal clear but upon skimming the top we noticed a white slimy film completely covering the pool liner.

We use Bacquacil pool chemicals and my husband closed the pool last winter with these chemicals.

We are currently adding water to the pool and have not attempted to treat the water yet.

Not really sure if we should use the vaccumm to remove the film or how to treat the water since we are not really sure as to what the film is. Thought might be white algae but it is a slimy film not floating white specks?

I would appreciate any help.

Thanks for the question Nancy

White slimy stuff is sometimes called Pink Algae and can be a problem with biguanide pools that use products like Soft Swim and Baquacil.

This is actually a bacteria, not an algae.

I suggest this post:

Swimming Pool Algae With Baquacil Use

This normally doesn't happen with chlorine pools. It can, but not likely.

You'll need to clean the pool including the ladder, ladder treads, steps, in all the crevices of the skimmer.

Pretty much any place where there is poor water circulation. Clean, clean, and more cleaning. To get rid of this, you'll need to do a good double, or even triple, pool shock. Bring your chlorine up 20Xs.

You can find the information for that at this link:

Water Mold

Here's the pages and charts to chlorine and pool shock:

Swimming Pool Chlorine

Pool Shock

This sounds like alot of chlorine, and it is, but being this is a bacteria and not an algae. It's a little tougher to get rid of so you'll need the extra chlorine. You can also put a small dose of diluted chlorine in the skimmer to flush out the suction side.

Whatever kind of filter you have, you'll need to clean the it out or backwash. You want to reduce the amount of Baquacil in the system. Don't put any Baquacil chemicals in the pool while the shock is going on.

I would encourage you to revisit the idea of using Baqucil and consider a chlorine pool.

Hope this answers your question.

If you have any additional questions or would like to comment on your post, you can find it at the bottom of the Water Mold page and the Q&A page in the "Swimming Pool Questions and Answers" page in the Water Mold category.

Have a fun and safe Summer.


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White residue all over floor of pebble tec

by Jeff

I was wondering if you might know what this white residue on the bottom of my pebble tec is. It appeared all of a sudden and its extremely hard to brush off. it just leaves a little cloud of white behind the steel brush im using on it.

Brushed it for hours and it doesn't seem like im getting anywhere. i thought maybe calcium but it appeared too fast. i just had a guest house constructed in my back yard and landscaped the whole yard aswell. it appeared around the time everything was done.

I have pictures, im not sure if it will let me send them in this message. please help.

Hi Jeff. Pictures would help but we can start with the troubleshooting and the process of elimination. You've had your pool for some time with no problems, then recently had a residue issue. First is the kind of chlorine. You should only use liquid chlorine as granular will leave a cloudy film on the bottom. Next is adding calcium chloride to increase the hardness. Maintain the CH at 150 - 250 ppm.

Without the filter kind I can only make general statements such as be sure it's properly working. Filters are meant to capture dirt. If the filter is not working then dirty water will go through it and be returned back to the pool.

Last would be the airborne debris from the new construction, coupled with a poorly working filtration system. Everything above means that some outside influence has caused the film. Pools normally don't "manufacture" things out of nothing. Through the process of elimination you can find the answer.


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