Venturi Skimmer Questions

[coastertrav]

Hello everyone.

In the final design stages in my pool build and have a nagging question.

Current plan is to use a channel drain in the bottom of the pool with a single venturi skimmer.

From my understanding the vunturi skimmer pulls more GPM through the skimmer basket without having to increase the suction from the skimmer itself than a traditional skimmer. The literature I have seen states that one of the benefits is that you can pull more from the bottom drain of the pool and pull less from the skimmer to the pump and have the same cleaning capacity or better than a traditional skimmer.

On the flip side, I have also seen and played with the idea of not including the bottom drain as I have seen other opinions on the fact that the bottom drain doesn't do anything special beyond allowing the pump and filter to pull from a large source to turn over the water in the pool.

Thoughts or opinions?

 

[kadavis]

Usually the Venturi skimmer is installed in conjunction with a infloor cleaning system, so in that case you would want all the suction from the floor drain

 

[proavia]

A venturi skimmer will also pull in more water volume at a given rpm than a standard skimmer. In theory, this should increase skimming action - especially when running at lower rpms. The venturi skimmer uses some of the water returning to the pool to help increase the skimmer intake volume. Here is one such design: QuikSkim Venturi Skimmer - A&A Manufacturing

The skimmer suction line and main drain suction line should be plumbed separately back to the equipment pad. A Jandy 3 way valve should be plumbed to those 2 lines, with the third leg connected to the pump suction. This allows selecting one source or a cobination of the two. Having the main drain will allow you to more easily do a full drain of the pool using the pool pump - as long as you have a multiport valve attache to the filter (or another way to pump water directly to waste). It will also allow you to continue to circulate pool water if your skimmer or skimmer suction line develops a leak.

As you're in Florida (high water table), the pool is probably going to have a hydrostatic valve installed. It may be possible to install this valve into the proposed channel drain. Without a bottom drain, this valve would possible be concealed by some type of drain cover anyway.

While you technically do not need a main drain, there can be some advantages to having one.