Sales, Service, Supplies and Consulting for Commercial Water Applications

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Boxers or Gutters?

Skimmer Boxes vs. Stainless Steel Gutters
How Important are They and What is the Difference?

by Roger E Anderson

As we travel to many different facilities, this question seems to be asked more and more. More so, what is the difference between having Box Skimmers and Stainless Steel Gutters?

Before we go too far let's step back and find out why we need either one of them? Common sense tells us that 90% of all pool contaminants come in through the surface. The other 10% come in through the surface. Have you ever seen anyone be able to spit underwater? Didn't think so. Dirt enters from the air, swimmers bring in oils and other contaminants, which all enter from the surface. Our conclusion then in all our wisdom is simple, keep the surface clean and the rest of the pool will stay cleaner. What is not so simple is how this is accomplished.

To effectively remove debris (spit, hair, lint, and organic material) from the top of the pool we must have "Tension". Not that every day tension that some of us get from our pools, but "Surface Tension". How do we get surface tension? By maintaining correct water levels in our pool. The correct water level gives us surface tension, which is waiting to be broken by either the gutter system around the perimeter of the pool, or by the skimmer boxes. If water levels are too low, we lose all surface skimming action and the dirt and debris have no where to go but down, in which it could be literally days before it reaches the main drains at the bottom of the pool. If the levels are maintained at a high mark, we end up flooding the gutter, which results in little or no skimming and zero absorption of wakes and backsplash caused by swimmers. To get an idea how this works, try an experiment. Take an empty 5-gallon bucket out to the pool. Push it down into the water until just the rim starts to break the surface. Watch what happens to surface pool water debris. It goes right for the bucket as it starts to fill up. Now, if you could pump the water out of the bucket as fast as it was going in, (almost like pumping water through your filter system, isn't it?) we would have constant surface flow. If the bucket is too high, we have no flow and if the bucket was too low, we would flood the bucket and the pump could not keep up. We would have very little, if any water flow from the pool surface.

What are some of the advantages and disadvantages of each system? Good question. Box skimmers are less costly than the stainless steel gutter system. Some of the disadvantages for box skimmers are that they are placed only every 20 feet or so which in turn creates dead surface areas. Strainer baskets need to be cleaned from each individual box and replaced at times. Piping to each box is under the decking around the pool. If you need a pipe fixed or the box itself, you are going to have to break up the concrete/tile deck. Very costly. Winterizing an outdoor pool with box skimmers can be a nightmare. Each individual box needs the water blown out of it and then insert some kind of a winterizing plug. This also needs to be done with each return inlet.

Stainless steel gutters have a very distinct advantage. Their supply of water comes from completely around the pool. Not just every 20 feet. Another advantage is they are constructed of two separate channels. One channel within the other. The inside channel being the water supply back to the pool. It is all contained within the gutter system itself. There is usually only one area with piping under the deck.

A properly designed stainless steel gutter system including a surge/balancing tank can incorporate winterization valves. All gutter water is gravity feed into the tank. The tank drain valve can be left open all winter in case of melting snow or rain that enters the gutter during the off season.

Even the best-designed system must still be maintained. Gutters with non-operating ball floats in the surge or balancing tank are rendered worthless. Box skimmers with broken or missing weirs on the front, same thing. Worthless. Go ahead and get "On Deck" and take a look to see if your surface is doing the rest of your pool any justice.