What to do with a green swimming pool.
When a swimming pool has gone green over winter or it has turned green during heavy use, you need your swimming pool back in action.
First things first! HOW GREEN is the pool?
I know that sounds like a daft question, but establishing how bad things actually are is important to deciding how to tackle the job, wasting as little water as possible.
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1. This is a slightly green pool and should be brought back quickly with correct use of chemicals and filtration. |
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2. This is a very green pool that has been negelcted over winter, although it looks bad there is very little debris. |
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3. If your pool looks like this, best to get in some big game hunters. Dont worry, it can still be saved. Just needs more work. |
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Slightly Green Pool
We will call the pool slightly green if the water is a lime green and we can still make out the bottom of the pool. This can be the easiest one to fix. The first step is to take a reading of the chemicals. You are looking for a test reading of min 1.2ppm and max 3.0 for chlorine and a reading of around 7.2 for pH.
If the test reading shows that chlorine is very low or zero
- Add chlorine granules (probably around 1kg for an 8x4 pool), retest after the chlorine has dissolved.
- Adjust pH level, this balances the water to make it harder for algae to grow and ensures that it is safe for bathers.
- Run filter for 24 hours.
If the test shows that there is chlorine present, this means that there is not enough "free chlorine", to sanitise the water.
- Check & Adjust pH level as above.
- Use a propreity shock treatment such as RapiChlor (powdered unstabilsed chlorine) or Superchlorinate with unstabilised liquid chlorine.
- Run filter for 24 hours
Both of the actions reccomended above would probably benefit from addition of a floculant sache, to assist the filter. Ensure that the filter is adequately backwashed. Do not swim in the pool until the chemical levels have been checked!
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Very Green Pool
We will call the pool very green, if the water is a deep green, the bottom is not visible and there is some debris and mosquito larvae. It assumed that the pool may have been neglected for a few months.
- The decision comes now whether to drain the pool or not. Cleaning the water up is not a problem, but we have to remember that this will use a lot of water. If the swimming pool has any signs of limescale or calcium deposits, drain it, acid wash and refill it.
- If there is no sign of calcium deposits, then we need to start the process of cleaning the water, this will problem take 3 cleans over a period of 4 days.
- Set pool filter to "RECIRCULATE" and add 5kg of TriChlor Granules, spread evenly over the pool surface. Check and adjust pH. Brush the bottom and sides with a pool brush, this will loosen any deposits and help mix the chlorine through the water. Leave the pump running.
- Once the pool water starts to look blue (will still be very very cloudy), add 5l of floculant. Pour this into the stream of one of the jets, allow the pump to run for a further 20 mins.
- Turn off the pump. Leave the pool over night, by morning most of the debris will have sunk to the bottom.
- Put your hoover and pipe in the pool, set the valve to "WASTE". Hoover the bottom of the pool slowly, trying not to stir up any dirt, the water from this will go down the drain -to waste.
- Once you have finished hoovering, set the valves back and put the multi valve to recirculate. Check chemical levels (dont worry if chlorine too high at this point) add more chlorine if its low. Run pump for the rest of the day, then turn off and leave overnight.
- Repeat 5,6 and 7 as necessary.
- Once there is very little debris, put the multi valve to the filter position, check chemicals and run as normal.
Then your pool should look like this -
Very Very Dirty PoolIf your pool looks like top right, then its best to drain it. It is quicker in the long run. If the pool is that bad, it has either been abandoned or left in a place where a lot of debris has gone into the pool. This creates a problem when draining because the pool pump is not designed to pump water that dirty. It will put a lot of strain on it. Its recommended that you hire a petrol driven pump, so not to damage your equipment. |
Specialised Pool Repairs can hire you a pump for 35€ per day, it has a 4.5cv engine and will pump up to 45,000 litres of dirty water per hour.
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