How to clear a green pool
Do you need to learn how to clear a green pool? Is your pool a murky green swamp? Is your pool so bad that you refuse to invite guests over because they will see you as a miserable failure in the pool cleaning department? Even worse is your green pool memorialized forever on Google Earth for the world to laugh at? I thought so.
Go ahead and have a pity party and then let’s get to work. Over the years I have cleaned hundreds of green pools for folks. It is a lot of work, but it’s not out of the scope for the average pool owner to accomplish for themselves. It will take about a week and some dedication on your part. You maybe thinking of draining your pool and refilling. This is frequently not a good idea as water is expensive and also you stand a chance of your empty pool vessel actually floating out of the ground while it’s empty which can be a financial disaster. Unless your water has something like oil or a decomposing body in it, you can save it. Trust me.
Get your supplies first.
Your going to need chlorine and lots of it. The pool in the photograph was approximately 15000 gallons and I used around 10lbs. of chlorine shock to clear it. I also used a metal-out product and some muriatic acid. Here are some examples of what you will need…
Now only buy what you need not all four of these products. I usually only need 1qt. of metal out. The shock you can get in 1lb. packets or just get a 25lb. tub and use the left over as needed after pool is clear.
Get your water circulating next.
If your pool went green because of a faulty pump you need to get that repaired before going any further. The water must be circulating around the clock before you can start to treat it and clear it. If you have a cartridge or DE filter you need to clean those also and probably clean them again several times before the water is clean again.
You want to skim any leaves, muck and debris off the surface and clean out your skimmer baskets. Even though you may not see the bottom yet you can usually take your pool net and scoop out any heavy concentrations of leaves and debris off the bottom also. This is hard and messy work but it must be done before treating the water. Use your pool brush and brush any coated algae off the pool walls and steps. The algae is much easier to kill when it is free floating in the water and not attached to the submerged surfaces.
By now your pool will look like green pea soup, but that’s OK as it will be free of most of the heavy and rotting organic debris and ready to circulate. Turn on your pump and check to make sure that water is flowing freely out of the return jets in the pool. Take note of the pool pressure gauge on the filter as this will tell you when it’s time to clean your filter again.
Add your chemicals
Using your test kit make sure the PH is pretty close to 7.4 to 7.5 and adjust with either acid or PH UP as necessary. Next add the whole 1qt. bottle of metal out around the edges of the pool. Add about 4 lbs of shock by evenly broadcasting over the pool surface and around the edges. Keep the pump running 24hrs until the pool clears.
The next day you may have to clean the filter again to get good flow as it will be clogged with dead algae cells. If the pool still has any green in it add some more shock and continue with brushing the pool and getting any debris left over from the bottom. The pool will eventually become a bright cloudy blue which is a good sign as that means the algae is dead. Clean your filter as necessary to keep a strong water circulation and after about a week the pool will be sparkling clear and clean again.
The only way your pool will clear is to use a lot of chlorine and never let it get too low in this process or the algae will bloom again and you will have to start over again from the beginning.
Here is the result after just three days! (And a lot of hard messy work)