Suction and/or Floor Head Cleaning Systems will require more operating time to keep the same water cleanliness, AND, even with increased operation times, you still have a higher chance of getting cloudy or green pool water. Suction Side Cleaners Suction Side Cleaners are not recommended for water clarity or for keeping pool "water" clean. Suction cleaners usually REQUIRE you to shut off the main drain completely, and then the suction from the drain is diverted to the cleaner through 1 1/4 corrugated tubing and a 1" diameter or smaller orifice at the bottom of the cleaner. Needless to say, water flow through a cleaner verses water flow through a 2" diameter PVC drain pipe, is substantially less. Add to this that adjusting the returns as I directed in the previous step "May" result in most cleaners tying themselves in knots, or in them only cleaning a small circle of the pool.
This is “another” drawback of having Suction Side Cleaners. They will cost you about 25% to 35% more run time to get the same water clarity you would get with everything adjusted as you see here. MINAMUM! Sometimes it is as much as 40% more run time.
Yes, this is an additional "Cost" to owning Suction Side Cleaners. At least ½, if not ¾ or more of the suction is taken from the skimmer and drain, and often the drain s shut off altogether. Less water flow due to twisting turning corrugated hose of a much smaller diameter = more equipment operation time to get the same amount of water clean. God help you if your suction side cleaner, or baskets, or lines, … get plugged. No water flow = GREEN POOL = lots of chemicals = even longer operation times = lots more cost. (For better options click and read the sub-sections as well.)
Floor Heads Floor heads return the water at the bottom of the pool mixing freshly filtered water with the Dirty water. (In direct contrast with the method above. The above, “preferred” method is called “displacement”. Fresh, clean water is returned to the top outside edges of the pool, displacing the non-filtered, dirty water down and towards the center of the pool towards the drain, where ¾ (Or More) of the pool suction occurs. Floor heads mix all the clean water with the dirty water randomly. This is cleaning by dilution.)
DIlution results in much greater run times to get the same water clarity. You also need to run a much larger pump a lot longer, with floor heads to get the same water clarity.
Some of the “experts” I have talked to who put a big stress on "Turnover Rates", or the amount of water run through a pool system in a 24 hour period. What they leave out of their equations is, whether displacement is used or dilution. They have it wrong. It's not about the amount of “water you move through the system”, it's about the amount of “DIRTY WATER you move through the system” and turn into CLEAN WATER, and in how quickly you can do that. Here's an illustration:
Let's assume that you worked in a laboratory. Let's assume that you have (2) 3' tall 2’ diameter clear plastic cylinders that you can fill with muddy water. Cylinder #1 has a valve at the very bottom of the cylinder where you can let the dirty water out, into a small pump, and then return the cleaned water through another valve at the top. Cylinder #2 has the same valve at the bottom, same pump and filter system, but returns the dirty water through 10 valves that spin in all directions equally distributed throughout the entire wall of the cylinder. Your goal is to get the water clear enough that you would be willing to drink from it if for both cylinders, and to calculate the time it takes to get to this point.
Both cylinders are filled with equally dirty water, and are operating with the exact same equipment and suction location. (The Bottom center of the cylinder.) There are no differences other than the returns. You turn on both pumps at the same time. What do you see?
In cylinder #1, there is no mixing, the water at the top steadily gets cleaner, and the dirty water steadily moves further down the cylinder, further away from the surface and towards the drain. By the time the water is halfway down the cylinder, the water at the top is already clean enough to drink (If you had to.) You discover that with the setup in cylinder #1, you only need to turn the water over ONCE to get clear water. i.e. take out one cylinders worth of water and filter it and return it to the top once. Let’s say that this entire process takes exactly ½ hour to get all the water drinkable.
Now let’s look at the system that duplicates the floor head system. All of the floor heads pop up in slightly different directions each time the activate, and they are all fairly evenly dispersed around the pool, just like our setup for cylinder #2.
System #2 is designed to "Mix" all the water, kind of like using a blender of some type to mix all of the dirty and clean water together thoroughly, take a little of the mixture out, filter it clean, re-blending it again. Repeat the process, ..
So how long does it take to get to the EXACT SAME WATER QUALITY as Cylinder #1? Is it the same? Are we clear at ½ hour? Nope. How about double the operating time? No. Triple? No. How much longer does it take to get the water to pass water the same water clarity standards as cylinder #1? It takes 7 hours. 14 times as long to get the same water clarity as displacement.
While these aren’t the exact numbers, they do represent what is going on when we mix all of the fresh and dirty water together in the above experiment. The “turnover” rate for BOTH cylinders is the same. About ½ hour.
Let’s say that we could see about a 25% improvement in water clarity for every turnover of the water(Which is higher than reality.), if you thoroughly mix the filtered water with the dirty water and you have this improvement, here is how the numbers would go: ½ hour.) 75% mud, 1 Hour.) 56% Mud, 1.5 Hours.) 42% mud, 2 hours.) 31.5% Mud, 2.5 hours.) 23.63% Mud, 3 hours.) 17.72% Mud, 3 ½ hours.) 13.29% Mud, 4 hours.) 9.97% Mud, 4 ½ hours.) 7.48% Mud, 5 hours.) 5.60% Mud ....
This is the process of dilution. The first is the process of replacement. After 10 complete replacements of all the water in the cylinder #2, you are still drinking greater than 1/20th of a cylinder of muddy water, or mixing 1 part of the original muddy water with 19 of the clean. Sorry, but at 10 times of running all the water through my floor head system scenario, I still don't want to drink it. In laboratory experiments, it takes 14 hours to get water that is "MIXED" as clean as water that is displaced gets in 1/2 HOUR.
So is the turnover rate important? Yes. If you are only moving ½ the water through the filter in a half hour period, cylinder #1 would take a full hour. Cylinder # 2 takes 14 hours to do the same job.
ONE MORE THING. Normal pool “turnover rates” are usually once every 4 hours, and we are supposed to turn over all the water at least 1 ½ times every 24 hours during the cold, non-stormy, lowest usage, … times during a year. That’s a 6 hour run time/ day for a diving pool in the winter, using displacement. How long would you need for a pool using mixing? 14 times that. But only if you started with straight mud. We aren’t doing that. When we drain and refill a pool we do so with clean, fresh water. For this reason, we only need a 25-40% increase in operation times with floor heads, with a motor twice as large as the one used for displacement, and a comparable increase per hour in electric costs as well, to keep that water looking as good as the pump/motor half the size.
The Best Cleaning Systems
The best cleaning system will allow for the following:
1.) It will allow you to have 3/4 of the suction going to the drain and 1/4 to the skimmer for surface cleaning, and not completely shut off the drain and cut down the water flow from the bottom of the pool by 75%. (i.e. no suction cleaners)
2.) Ideally: It will not "MIX" the water at all, barring that, it will mix the water as little as is possible, and then let the normal pool filtration clean all the dirt stirred up by sucking it down the drain. (i.e. no floor heads.)
3.) The ideal cleaning system will not suck the debris into the skimmer basket, pump basket, or other basket, and thus suck all the water through the dirt, decaying plant and animal material, etc. making gunk tea. Also, on suction cleaners, the more debris picked up, the lower the suction, the more restriction, the more heat and wear and tear on pumps, filters, plumbing, … the less water flow, and the longer equipment needs to run to clean the water. The ideal pool cleaner will pick up all of this debris in a bag that isn't in the main water flow the entire time the main pump is on. (Floor heads usually pick up no debris, they just blow it around the pool, and, if you get lucky, eventually, it gets blown by the main drain. Thus, floor head systems really aren't cleaners. Suction side cleaners all suck the debris into a bag, or basket that all the water is then pulled through. Thus They are not the best.)
4.) The best cleaner will only run long enough to keep the pool surface clean, and it should only need about 15 minutes maximum for it to clean the floor of the average pool. Thus, even if they mix the water while operating, if you set them for the beginning of the filtration cycle, they will only run for the first 15 minutes out of the 8 hrs. normal summertime operation cycle. This leaves 7 3/4 hours for the drain to remove all suspended particulates using the displacement method described above.
5.) The best cleaning systems should be low in repair and upkeep costs. Since most home owners move about every 5 years in the valley, let's forget the lifetime warrantee to the original homeowner parts warrantees. (Note: they do not include labor after a year, just the parts). Most people will move into a home with an existing pool, and will have no warrantee at all. Average upkeep, with replacement costs for floor head systems is about $250 a year, and suction side cleaners over a year old is about $150 a year. With suction side cleaners usually needing a complete replacement of the unit in 4 years or less, bringing their total annual upkeep costs up close to the floor head systems.)
What cleaner fits the bill on all these categories? A Polaris 180(discontinued) and Polaris 280. Both will probably need a rebuild kit every 6-7 years, and a new bag once a year ($30 or less unless your kids try to ride them.). Yes, you need a booster pump installed and a separate time clock, but operations cost, and the fact that they will keep most pools spotless, most of the time (except steps and love seats), and do so in most cases, in 15 minutes or less, and you understand why I like them. Plus they do not get plugged up with debris and then let your pool turn green because you have no water flow. They also have no problems with tiny rocks to plug up the drive wheel, or small sticks to puncture a cleaners diaphragm. Yes, they are expensive up front. But how expensive are the other cleaning systems?
At over $250 a year in maintenance, not to mention more than double the cost of the Polaris system, what was said about displacement verses mixing, the larger pump/motor / electricity costs, … are we really considering floor heads? Considering how clean Polaris 280’s keep the pool, considering that you do not need a 1 1/2 H.P. motor or a 2 H.P. motor to run them (Like floor heads), and considering the time you can reduce your filtration times by up to ¼ or more, since you can adjust your skimmer and returns to function as they were designed, you will have payback, from a costs standpoint, in about 3-4 years, even based on suction cleaners. From a hassle standpoint, it pays for itself the first 6 months in most cases. |
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