You guessed it. Florida! After some research after posting, I am thinking that the black may also be algae. The gutters over the pool are the the wide ones already and built in with the cage so going wider would be a huge undertaking. I'm thinking it just stays wetter there more often.

I'll have to check at the pool store and see what is available. I also read where you can use liquid chlorine diluted in water. Is that what you were referring too when you mentioned bleach?

Thanks for the ideas!

Yes. I get the jugs from pinch a penny.

We had Kooldeck in our last home.....that's why I bit the bullet and put pavers in here!

I'm in North FL and keeping the acrylic clean was a consatnt battle. On top of that we had a lot of trees and the leaves would stain the deck. About once every three months we would clear everything off and put down a dilute bleach solution. We let that stand for a few hours in the hot sun and then came back and used a big push broom to scrub the surface. (I usually wore rubber boots when doing this.) Then a good rinsing with fresh water.

That would usually do the trick unless there were a lot of roof debris and leaves staining the deck. Sometimes we had to repeat the process.

Between the cleaning and the cracks that developed I was not happy with that type of finish in our climate. Maybe screening would have helped.

We love pavers!

I've thought of pavers but have no idea how much they would cost. That would look much nicer. Any disadvantages to pavers?

Our pavers were $6.50 a sq. foot here in Florida. Most are made in Florida so the shipping is not such a big issue as it is for other parts of the country. I like the pavers because its such a nice, textured look.

I know that this is an old post, but we had much the same problem, excluding the humidity in Melbourne Australia. These guys are able to fix by using products that are available in Australia. I believe that for the initial preparation they use a NappySan product (not sure whether it is available in the US). It is normally used for laundry, but it takes out the dirt, mould and algi. They then pressure wash and then use a stain that they guarantee for years.

Here is a link that might be useful: Pool Deck Cleaning

I’ve had Kool deck in several homes and it is impossible to keep clean. I’m fanatical about it. I wish someone would come up with a way to coat it so dirt, mold etc would not adhere. In the meantime I hose it regularly and the ONLY thing I’ve found to clean those stubborn spots is with a magic eraser mop. Takes scuffs etc right off. Don’t press too hard! You’ll wear out the mophead in no time at all. It doesn’t take much pressure.....literally takes dirt, mildew, scuff marks off like magic.

if Anyone out there has a solution for preventative maintenance I would love to hear. And you’d probably make a fortune. For now I may paint mine the color of dirt so I don’t have to be frustrated every time someone with muddy feet walks on my patio!