Hayward 1.85hp VS Pump ~ Trying to be Cheap Lessons Learned (playing with low speed)

[Holydoc]

Brand new pool with a Hayward T15 SWG and cartridge filters. So after the build when the pool was basically handed over to us to take care of, I asked the Pool Guy, "Why is the pump set to run for 12 hours a day, 6 hours at 50% power and 6 hours at 80% power?" His answer was that that was the way we normally set it up. Now granted, the pool ran beautifully at this setting. The SWG was set to 55% output and the surface of the water was skimmed nicely. However, I am a cheapskate and wanted to try to cut costs anywhere I could. The first thing I did was play with the 6 hour 50% power setting. My thoughts were that let me find out how low I can set the pump output and still have the FLOW valve of the SWG stay open.

Test 1 - Jack the power all the way down to 20% output. FLOW valve stayed active (kind of worrisome) and everything appeared to be working. However, what I discovered is that though the FLOW valve was still working, the filter started gurgling and making all kinds of noises by the end of the 6 hours. My discovery was that the pump was having a hard time keeping the water level up in the filter. Even when I opened the purge valve of the filter, you could hear the water rising and air coming out, but it would stop after a few seconds. The water would go no higher and no air out of the filter.

Test 2 - Turn the power to 30% output. Water rose higher in filter but no water would come out the top of the purge valve. Filter continued to gurgle. I continued to raise the power of the pump until water started pouring from the purge valve at 40% output. Filter was dead silent.

So what I discovered is that the actual reason behind setting the pump to 50% on the low setting was that it got sufficient power to pump water into my filter system as well as through the pool. I also saw that my chlorine production fell causing my pool to go from FC=4.5 to FC=3.5. So though RPM's are not in the SWG calculation, it is possible that the slower flow introduced chlorine a bit slower too.

Currently I have to pump set back to 50% for 6 hours and 80% for 6 hours. I plan on leaving the pump at 50% for the low speed for the time being. My next test after my pool's FC moves up a bit is to play with the high speed. I plan to run the low speed for 10 hours a day and the high speed for just 2 hours. If the SWG is not affected by the RPM's too much, then I should not see a drop in FC but should be able to save a bit of money by only running the VS at 80% for just long enough to ensure the surface is skimmed nicely.

 

[mknauss]

The filter will be full of water at all times, regardless of pump rate or even the pump being off. If not, you have a suction side air leak.

 

[Holydoc]

The filter will be full of water at all times, regardless of pump rate or even the pump being off. If not, you have a suction side air leak.

You are correct. I should of expanded a bit more. The system did not introduce air in the filter. I did. I had cleaned the filter which had dumped the water from the pump and the filter. I mentioned this in another post and should have quoted it here. The point there was that with an empty filter, it took turning the pump up to 40% strength to refill it. 20% would not completely fill the filter with water. It took me reinspecting everything and hearing the filter making noise to realize this.

And no, I do not have any suction side leaks. My pump and filter does stay constant once everything shuts off. Of course if you open the bleed valve and take out the filter drain plug....well, that is a different thread. LOL

 

[mknauss]

If you induce air into the system, it needs to be bled out of the filter using the bleed valve. It will not clear the air on its own without very high flow rate.

 

[Holydoc]

LOL... I know that. That is exactly what I was talking about. At 20% power with the bleed valve open, the pump would only push about half of the air out of the filter. At 40% power the pump could actually push all the air from the filter and water would finally come out the bleed valve. That is what surprised me was that the filter would still retain air in it causing a gurgling sound.

Sorry for the confusion.

One of the reasons I wanted to take the time to mention this experience here is that I have read a few posts where the poster was talking about their filters making noise. Maybe if they are getting all their intake water from the skimmer, there is some air being introduced that is working its way to the filter where it is trapped and making the noise. Possibly turning up their pump just a smidgen may be enough to keep that air from residing in the filter?

Marty thanks for your input and for helping me clarify things. I guess I was so excited about testing and learning about the equipment on my new pool, that I forgot to type all my thoughts. LOL

 

[mknauss]

At 20% power with the bleed valve open, the pump would only push about half of the air out of the filter.

Something is wrong. The pump should easily push the air out of the system. The filter is plugged, the bleed valve is plugged, or some thing else is restricting your water flow.

 

[Holydoc]

So if the wattage being used on the Hayward controller is correct and if I only ran the pump at 50% for 12 hours a day, it would cost me approximately $10/month to run the pool. Of course this does not count the cost of running the robot to clean it twice a week, the cost to run the SWG, or the pump for the waterfalls that I run every day for an hour (or for aesthetics and sometimes to help cool the pool).

Running it at 40% would shave a couple dollars off of that monthly cost. Of course we are talking only a couple of dollars a month savings, so my next tests will just be for my own curiosity and nothing game changing.