Balancing skimmers

[Just Chris]

Our pool has two skimmers at one end, and they appear to be connected to a common return.  One skimmer, however, seems to assume priority to the detriment of the other, which is then useless.  If I block the strong one, the weak one is OK.

Is there a means to better distribute the flow between them?  Perhaps some sort of threaded restrictor to screw in the stronger one?

Chris

[Poolguy]

No If you do that then you are restricting the flow from the skimmers which will decrease the amount of water you are circulating.

This is a common problem in France. Pool builders in this country seem to not understand the simplest of hydraulic theory. That is if you connect more than one entry or exit piece (skimmer or return) via the same pipe then the first will naturally get the lions share followed by the second third, etc The one on the end of the line is usually there just for decoration - as it gets nothing. That  means very poor circulation and naturally, a green patch in a corner occassionally.

The remedy for this is simple but not inexpensive.

Each white fitting in the pool should have its own pipe feeding it. that is:

• if you have two skimmers then there should be two pipes entering the pump house where they are collected and feed to the pump
• one more pipe for the Bottom drain and
• another for the Vacuum point

That could make a total of 4 input pipes

Treat the returns the same any you have two, three, or even four pipes returning water to the pool.

 

In my experience in visiting pool in France I have only seen this once made by another builder and that was his first pool (good job)

Naturally, I always build a pool that way as it correct and will ensure that every white piece in the pool can be controlled and does it job- that is to circulate water.

You can see how this might look here http://www.poolguy.fr/products/circulation.htm

Sizing is another issue as mostly the pipe sizes are insufficient but that’s another discussion.

Andrew

 

 

[Just Chris]

Thanks, Andrew.  looks like I'm stuck with it, then.  There doesn't seem to be any discolouration around the weaker skimmer, in fact it's not really a problem at all.  I suppose just swapping them over from time to time is harmless...

As a postscript, I've been thinking about this overnight - if one line services 2 skimmers, and (as you say) the first in line does the larger share of the work, swapping them over shouldn't make any difference overall.  Surely, then, if you reduce the flow through the stronger one, the flow through the other will be forced to proportionately increase, and the net throughput through both must be the same as before?  You're the expert, Andrew, and I may have misunderstood - my physics never were that good!

I fully appreciate that in ideal circumstances, each skimmer should have it's own controllable line to the pump house, but that obviously ain't gonna happen without some serious excavation!!

Chris