UV light not coming on unless VSP is set at 2800 rpm

PascagoulaPool

Bronze Supporter
Nov 6, 2019
7
Pascagoula, MS
We have had our pool for less than a year and I am just now trying to get things fine tuned.

~10,000 gallon gunite pool/hot tub, Jandy AquaLink RS, Jandy 2.7hp VSP, Jandy 460 filter, Polaris with booster pump, Rheem heat pump/chiller, Jandy natural gas heater, Ultra UV2 light, inline tablet chlorinator, sundeck with 2 bubblers, 2 deck jets (typically off). (Stenner 15 gallon tank and pump for liquid chlorine on order and will install after inline tablet chlorinator.)

Our builder included an Ultra UV2 light as part of the build. I was not to sure what to think of this because everyone that I know has a SWG. I asked at the pool store and the owner said that this was the type of system that he had so I went with it. I also upgraded to a VSP pump to try and save some money long term on electricity. However, when the pump was first started up the UV light would not come on at lower RPMs. We finally found a combination that included shutting off the bubblers for the sun deck and setting the RPMs to 2750. This was fine until I realized that there was no circulation to the sundeck and had to increase the RPMs to 2800 so the UV light would come on with the bubblers turned on. Looking at the instructions for the UV light it looks like it should have been installed between the filter and the heat pump. My builder put the UV light after the gas heater (filter >heat pump >gas heater >UV light). Any suggestions?

Also, I also just noticed that the door on one of the skimmers was not installed. I know that they didn't install it because there is grout blocking one of the side holes where you would install the door. The builder said that they usually don't install them because they typically get stuck in the up position and end up taking them off anyway. However, the skimmer with the door collect 3x more leaves than the one with the other door.


IMG_5124.jpegIMG_5125.jpegIMG_5126.jpegIMG_5127.jpegIMG_5128.jpegIMG_5129.jpegIMG_5130.jpeg, Jandy VSP,
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,535
San Dimas, CA (LA County)
Unless your pool is indoors, you don't need extra UV. It only kills what goes through it anyway and leaves no residual. Since you aren't emptying one pool into another through the UV, you'll never get 100% anyway. Unplug it.

You need a skimmer weir.

Think it through. Water seeks its own level. As the pump sucks water out of the skimmer well, pool water flows into the skimmer well through the throat to maintain the level. So far, so good?

If the cross section area of the skimmer throat is 3"X12", that's .25 sq ft. Let's say the skimmer is pulling a measly 100 gallons per minute. That's 13 cubic feet per minute. That means the flow coming through the skimmer throat will have a velocity of 52 ft/minute to maintain the water level. Now reduce that opening to 1/2"X 12". That's 1/6 the area so to maintain the water level that water is moving six times as fast or 312 feet per minute. That's a pretty good clip - 3.5 miles per hour; enough to overcome slight breezes and currents and pull water into the opening. The weir is critical. The skimmer weir limits the flow coming in to maybe the top 1/2" of water. Less water above the weir means faster current. More water above the weir means sluggish flow.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
17,843
Bedford, TX
he builder said that they usually don't install them because they typically get stuck in the up position and end up taking them off anyway. However, the skimmer with the door collect 3x more leaves than the one with the other door.
P,

Your pool builder has no clue how a skimmer works.. The Weir door is what makes a skimmer... skim.. Go back and demand that he install the missing door.

As far as your UV goes, it will not make any difference if the light is on or not... I wish there was a way to prove that by making some test, but it is kind of like "ghosts".. You either believe in them, or you don't, you can't prove it one way or the other... :mrgreen:

Thanks,

Jim R.