Swimming Pool Skimmers

The most difficult job on a regular basis that you pool owners or professionals have is just keeping the pool clean. The first line of defense against the dirt that gets in the pool is the skimmer. [Warning: New knowledge ahead!]....Have you ever noticed that when the wind blows during the spring's windy season or the summer's monsoon, dirt and dust are blown around? I'm sure you have!.... thats because it doesn't stick very well to concrete or any hard surface, even other dirt. But boy does that stuff ever stick to the surface of water. Have ever you noticed no matter how hard the wind blows, it never blows anything back out of your pool? It is a one way street here, garbage in, garbage never comes out. So, the skimmer's only job is to pull dirt, leaves, insects and all sorts of nasty debris off of the surface of your pool and deposit those items into the basket. That basket gets to be emptied by you.

I've always tried to avoid doing a too close of an analysis of the skimmer basket's contents.... NOTE: [Warning: All warnings from now on are real!]....[Warning: Sometimes live/dead rattlesnakes, other colorful snakes, dogs, cats, Scottsdale rats, frogs, rabbits, skunks, birds, scorpions,and weird insects are found inside your skimmer basket! Sometimes these dead animals, and insects want to bite, or sting you, but mostly they are in the process of moving toward a bad state of decay and tend to fall apart and stink really bad!] Yuck! This is one of the reasons I gave up pool service and got into pool repair! You have to watch out for insidious plant (Triffid like) debris too: sometimes there will be a sharp thorn in the skimmer, sometimes there will be a poisonous, irritating, or blistering leaf in the skimmer. Always dread taking the lid off the skimmer. Always dread having to look into the basket. Always dread having to look into your pool, you may see something moving around, something you don't want to deal with, anyway:

Use latex or vinyl gloves to clean out the basket or use an old pool serviceman's trick, that is to have two baskets. One to pull out of the skimmer and let dry out, and the one laying around the pool equipment from last time you forced yourself to service the pool, the one that is already dried out, which now is easy to dump the contents out of, by tapping it on the fence or something. Sometimes you find the skimmer basket and diverter valve ajar. This is not a good sign. It will be covered in a later post. But just note that because of this, sometimes these critters get sucked up and stuck in the pipe running back to the pump, or get deposited and compressed into the very small pump strainer basket. Yuck #2.

There are different makes of skimmers out there for residential pools, but over the years it appears that the basic design has settled down to the following parts: there is a lid that should be flush with the cool deck, if you pull the lid off and look down you should see a basket. (NOTE: If the sun has been shining on the lid it may be hard to take off, just pour some pool water on the lid, that will cool it off and shrink it making removal easy). Go ahead and pull the basket out. Once the basket is out of the way there should be a water control valve, sometimes known as the diverter valve, below the basket. It should be about six inches wide and look like a mini flying saucer, or maybe it is the size of a flying saucer. It's job is to regulate the suction of water between the skimmer opening and the main drain at the bottom of the pool. If you turn the water valve aka diverter valve over, you will see a plastic or metal flap that may be partially covering an opening. This is the actual water control mechanism. If you don't see that flap, go buy another one. A metal one if you can. They are stronger, and don't break, just bend. That flap is an important part. Get one. Don't forget to buy the stainless steel screw that you need to attach it, any other type of screw will rust quickly and you may be hunting later for that metal flap. It will either be in the pump strainer basket or stuck in the pipe between the skimmer and pump.

If you move that flap completely over the opening at the bottom of the diverter valve, and place it back into it's original position and turn the pool on, the skimming action will be almost completely shut down and most of the water will be drawn by the pump from the bottom of the pool via the main drain. The times you may want that flap in that position is when, for instance, you have just finished brushing down the pool, or when the pool water itself has become full of suspended dust from a dust storm.

If you move that flap completely away from that opening, and place the diverter valve back into it's original position, nearly all the water will be drawn by the pump through the front opening of the skimmer and very little water will be pulled in from the main drain at the bottom of the pool. So the skimmer opening at the water line will be the only source of water for the pump. You will want the diverter valve to be set in this position, and the pool on, during windy conditions or dust storms. Many times I have set the flap to be in a in between position, so that some water is pulled from both the main drain and the skimmer at the same time. Another thing to look for is a rubber o-ring at the very bottom of the skimmer housing, against this o-ring the divertor valve should rest. If this o-ring is missing or worn, replace it with a new one.

The last part of the divertor valve that I will talk about is the hollow float in it's center. If you hold the valve upright in your hand and shake it, you will see that float is loose and not connected to the rest of the valve. When your swimming pool's water level gets too low, do to some problem and air is detected by the float, the lack of water will cause it to drop down against the bottom of the valve and shut down the skimming action. The pump will now draw water exclusively, but temporarily, from the main drain at the bottom of the pool. Hopefully, you will be around to take corrective measures. Otherwise, the water level may continue to lower and the pump may be starved for water due to debris being pulled up from the main drain and being deposited directly into the very small pump strainer basket. Depending on how long this condition lasts, that small basket will fill up. If not cleaned out in time, a melt down in the pump housing will ensue. You may get a warped pump housing, wherein or whereon there may be several water or air leaks. A very fascinating and artistic, piping situation in and around that over heated pump may present itself: you may be the proud owner of warped piping that now looks like it belongs in a famous Picasso painting.

The next part of the skimmer you need to know about is the weir. Lay down on your tummy on top of the skimmer area. Look over the side of the pool into the skimmer opening at the side of the pool. You should see a rectangular flap of plastic about six inches across. This is the weir, it is attached by screws to the walls of the skimmer opening. It happily floats to wherever the water level is. Its function is to enhance the flow of water into the skimmer (skimming action). When the pump is off, the weir should be floating partially above the surface of the water. If you turn the pool on and the weir is properly installed you should see that the position of the weir has changed. Now the weir is completely submersed below the water line with no less than about 3/4 of an inch of water rushing over the top of it. By restricting the flow of water to a smaller area, the speed of the flow/skimming is increased tremendously.

Sometimes the weir or the walls of the skimmer opening to the pool become warped through the years, because of exposure to the summer heat. The weir may get stuck in an up or down position in this case, either stopping the flow of water or reducing the effectiveness of the skimmer. Go to your local pool store and get a smaller, spring loaded weir.... if you buy a exact duplicate of what you have, it may be hard to get it screwed back in and it may just get stuck again. The downside to the spring loaded weir is: now you will have to check it on a regular basis. It has a tendency to move upward in the skimmer. Remember to install the new weir in the proper direction. The hinged part is nearer the pool itself, the other side, the one that moves up and down the most and is closest to the water's surface faces towards the skimmer basket. If you put the skimmer's weir in backwards, it will immediately rise up, seal off and block the flow of water into the skimmer, as soon as the pump is turned on. Also try to install it in the same place as the original. I have, in a pinch, temporarily replaced a weir with an appropriately sized and shaped rock or rocks! If you do this, be sure that the pool's water leveler/filler is functioning properly. Rocks do not float up and down as well as weirs.

You would be surprised at how many times I have been in a customer's backyard, doing a repair on some part of a pool, only to discover that some part of the skimmer is missing. Perhaps the weir, basket, or the diverter valve is missing, broken, or just set up wrong, or the basket is completely full of debris and restricting the flow of water to the pump.

Another problem I ran into repeatedly is that during the summer, some pool owners try to save money by not running the pump long enough. Don't you do that! Not running the pump is going to cost you in other ways, the water will not be filtered as well, the skimmer won't work properly, you or your kids or grandkids may get odd infections, and guess what?....You will be spending a lot more time cleaning your pool. You don't like doing that do you? So the skimmer must have the pump on to do it's job! If you want to save money on electricity, do it in the winter when the water is refrigerated, and the pool isn't being used, even turn the pool off in January, it will be OK.

Now, I know that the cost of the electric bill gets sky high in the summer. Running the pump eight hours a day will cost you about twenty five to thirty bucks a month. Be aware that refrigerating your house is why your bill is high, not because you are operating your pool's pump. When is the best time to run the pool in the summer? If money is no object, then all of the time, if noise is a problem for you or neighbors then adjust the time accordingly. If money is an issue, then run the pool between the hours of four in the afternoon to midnight, Why? Because windy conditions occur in the Sonoran desert during or just before this time. Why wait until all the dust, dirt and debris from the latest dust storm become waterlogged and sink to the bottom of the pool? Now that stuff is going to be harder to get out. An annoying problem in this regard, (Am I complaining too much?......Nah!) is when some pool owners subscribe to an electrical program that rewards them with a discount for using electricity during certain parts of the day. Run your pool during the evening anyway. Remember: The skimmer is your first line of defense against a dirty pool. Use it! The next post will cover skimmer placement and pool orientation.