FlowVis installed - question about rates - vs pump on the way

rcy

LifeTime Supporter
Apr 25, 2009
345
Burlington, ON, Canada
Hi all. I just installed this FlowVis in preparation for a TriStar VS900 variable speed pump being installed in the next few days.

My system is currently a Tristar non VS and it shows 1 HP and 1.85 HP (I think maybe it says SF here as well - service factor, whatever that means). I have a sand filter (S244T), 9 techno solis solar panels on the roof. The line from the skimmer is 2" and everything after the pump is 1.5"

Currently, with the solar off, the flow rate is about 55gpm and with the solar on, it's about 45gpm. The pressure gauge on the sand filter shows 21psi with solar off and 27psi with solar on.

I 'think' the 45gpm is good with the solar on, but I've always (since day 1 - in fact I think I might have posted a few years ago wondering if my pump was too powerful or my filter too small) wondered if the flow was too great for the filter. If I'm understanding the s244T manual correctly, the maximum flow rate for 1.5" pipe should be 45GPM.

What do you all think is a good flow rate to aim for with the VS900 when it gets installed? Opinion for solar on and solar off would be appreciated.

Thanks.




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CJadamec

TFP Expert
Apr 29, 2016
2,248
Quaker Hill, CT
Your filter is rated for 62gpm so you should be fine there.

As for pipe size 1.5 inch pipe can move up to about 60gpm before it becomes really inefficient to move any more water thru it. You can technically move as much water you want through any size pipe if you have enough pressure. The pressure will rise rapidly as you go over 45gpm in 1.5 inch pipe which is partly where your higher filter psi numbers are coming from.

I might be off on this number but I think you want to shoot for about 6gpm per solar panel. You have 9 panels so you would want around 36gpm through your panels. I would shoot for about 40gpm when your solar is on.

As for flow with solar off I would set your VS speeds to the lowest speed possible to make everything work. If you are just circulating and skimming keep lowering the speed until stuff doesn't go in the skimmer any more. If you are generating chlorine with the salt water generator set the speed a lil higher than min for the flow switch to close. Same goes for your gas heater as you SWG.

Your aqualink panel should be able to manage all the different speeds automatically for you once you program it.
 

rcy

LifeTime Supporter
Apr 25, 2009
345
Burlington, ON, Canada
Thanks. I have an older Jandy PDA system (2007), so there aren't any options to control speed via that interface. Instead, I'll be using the Jandy PDA for timers, and the speeds will be controlled at the pump (I need to utilize the pump relay and the Valve Actuator ports inside the Jandy panel which will then 'tell' the pump to run at whatever speed is set).

How did you come up with 36gpm for the solar panels?
 

CJadamec

TFP Expert
Apr 29, 2016
2,248
Quaker Hill, CT
I did the math wrong that's how. 9x6 = 54 :hammer:

But you should look up the info on your panels it should tell you what the recommended flow per panel is.