Two pumps for a swimming pool of 130 m3?

[zappalot]

Our building swimming pool  has about 130,000 L of water. Time and again we have a green swimming pool because of poor maintenance and untrained staff. After I really put a lot of pressure they came with a new story to explain why the pool went green again.

 

There is only one water pump. We would need a second one.

That is just nonsense, right? For what would you need a second water pump? They claim if only one water pump is running all around the clock wear and tear might cause a problem..  It's too much work for just one water pump.

 

What does this has to do with an algae filled swimming pool?

[grollies]

Nothing, especially if your pump is running 24 hrs.

 

Mind you, depends on your pump spec right?

 

Are you asking why your pool water is green?

[sappersrest]

I would guess by the previous posts pools are not your forte?? I  would suggest you take out a contract with a pool company on the provision that for every day the pool is green you deduct a penalty.

 

If the pool has an insufficient turnover then the ability to disinfect the pool diminishes.Dead spots encourage algae growth.

 

A pool in a common area or resort should have a max 3 hour turnover i.e. in your case a flow of  43m3/hour

with 2 no 1000mm dia filters.

5 inch suction to give you a flow velocity of 1 metere /sec and a delivery pipe of 4 inch.give you a flow velocity of 1.5 metere /sec

3 pumps 2 run one standby, rated suitably to cope with the head pressure and required delivery.

If you can't match the above you are going to struggle.

Then you are going to have to rely on good maintenance a plenty of chlorine, certainly not a once a week visit.

In the UK I used to do a lot of training and inspections for school pools and one of the big problems was that the caretaker did not have enough available time to look after the pools and thus pools turning green was a big problem.

 

Just to recap.

Your pool will turn green if you have  insufficient free chlorine try to aim for a steady 3.5 ppm.

Also high levels of cynuric acid will also not help as once it gets too 100 ppm it will start to reduce  the the effectiveness of the chlorine greatly.

Try and keep the ph to around 7.2 this makes the chlorine more effective.

 

I should imagine like every largish pool that has been badly looked after your cynuric acid levels could be through the ceiling the only way to test this accurately is to use a tester  

For this test strips will do, carry out the test as instructed  if the reading is high or above 100 cary out the dilution process as  previously described to get an accurate reading.

You should be aiming for 30 -50 ppm

One we get over  50 ppm the effectiveness of the killing power of the chlorine is diminished  over a 100 you are heading for disaster green pool/ milky pool is generally the first sign.

 

The only way to bring the levels of cynuric acid is by dilution