Just because you have covered your pool, does not mean you can forget about it if you want an easy and potentially green-free opening. There is still a little bit of work that needs to be done.
1: Most importantly, close your pool late and open early.
Yes, I know that you are not going to swim during the frigid times between September and April, depending on where you live, but you do need to prepare your water for when you DO want to swim. This is one of the biggest things you can do. Closing the pool in November and opening in March will help it not be a lovely shade of swamp green come May. Think of the pool as a nice pretty crock-pot. All those contaminants are just brewing under the cover and when the temperature rises, so will the algae growth! Any time the water is above 62 degrees algae can grow, so the longer you can keep chemicals in and circulating the better off you will be.
2: The easiest part of winter pool maintenance is simply keeping your winter cover clean.
This would include going out every once in a while and blowing off the leaves and other debris that have accumulated on the cover. If they are too heavy, then simply hose them off. This will allow the cover to be easier to remove, as it will not be as heavy. Also, the cover is easier to remove when you are not worried about debris falling into the pool.
3: Also, make sure that the winter cover is not bogged down with water.
Keeping a little water on the cover is great, but too much can stretch out the cover and put additional wear and tear on it decreasing it’s life span. If you do not have a cover pump, you can use a shop vac to get the excessive water off. This may or may not be a problem for you depending on the type of cover you have. Many in-ground covers are mesh so they allow the water to run through, preventing the build-up of water. However, some in ground, and almost all above ground covers are solid, so they will accumulate quite a bit of water, depending on the weather where you live.
4: As soon as the water unfreezes in the late winter / early spring, lift up the corner of your cover and add a little liquid chlorine.
You will need the pool type of liquid chlorine, as it is stronger than the bleach you buy at the store. This will help to break down all the contaminates in the water. Whether you have a solid, HD mesh, or mesh cover, contaminates can find a way into your pool. Usually these include, but are not limited to: bird droppings, pollen or left over bather load from last year’s season. This can be added even if the pump is not running.
5: That’s it!
Removing your cover in the spring to a sparkling clean pool really isn’t just a fantasy. It can happen. However, you just need to take the right steps during the fall and winter to give you that crystal-clear water.