sounds silly but im not sure i have algae...

i closed my pool last labor day clear. Ive been out there over the winter and have checked the water sevaral times. I have a mesh saftey cover on the pool so its hard to see the water clearly unless you lift the cover far off. The water looks dark and merky when looking into a corner with the cover lifted off. ive shined a flash light in and can see the bottom and also have taken a gallon sample of the water which appers clear.

The bottom surly is dirty and has needs a good vacuuming. Im trying to determine if the water is has algea or is it the dirty bottom and lack of light giving me the impresion the water is alged filled. I assumed once winter temps hit any algae would either die or no longer grow. Its been warm here in md but i dont think water temps are higher than 50-60 at most since its been hitting 30s at nite.

I did check and thers no fc in the water but i believe the waters still too cold for algae growth.

Hi Pbotz;

If you've got a liner or fiberglass pool, feel the sides. If you have early algal growth, the sides will have a slimy / slippery feel.

BUT . . . with a mesh cover, you NEED to add chlorine or you WILL have a mess on opening. I'd recommend adding 2 gallons of bleach per 10,000 gallons of water. You can pour it through the cover, but have a hose ready to rinse it off right away, once you are done. Pour in multiple places around the pool.

Then, retest after 2 - 3 days. If you have no chlorine, repeat. Continue adding bleach every 2 - 3 days, until you have and can hold a FC residual. Doing so will make startup MUCH easier.

yes , vinyl liner. i will check next time if its slippery or slimy. i usually add bleach once the weather warms up but dont now cause i feel its too cold at nite for algae to grow. Am i wrong about the temp and algae growth. Its a welcome site when the warm weather arrives but than the pool maintenance begins. I thought a mesh cover was a good idea but have since figured i should go with a solid cover.

We used to say that algae couldn't grow in cold water ........... until fellow moderator Al, (Poconos), found algae growing under ice in his pool in northeast PA. I think he posted that picture here on the forum somewhere a few years back. Not sure if it is still around or not? Maybe Ben knows, or if not, I'll ask Al to repost it here.