varios6 flow question

[Jeff Crawford]

If the varios6 pump return in the tank is a 3/4 inch pipe does it still increase flow/reduce head pressure to use 1&1/4 pipe from the pump to the UV that needs at least 1,500 gph?

 

[blaxsun]

What’s the wattage of your UV and the size of your tank?

 

[Jeff Crawford]

It’s a 40watt pentair , pretty big, 1/1-2 in and out, the out on the varios6 is 1/1-4 inch , so I spend $150 more for pipe and fittings for 1-1/4 inch to go from pump to Uv to reduce any pressure loss from elbows through 1 inch , my hope is it will push through the 3/4 end pipe faster , at least around 1500gph ,,,tank is 220 half cylinder

 

[DCR]

The 1-1/4" pipe will help, but there is no way a Varios 6, or most any other aquarium pump, is going to push 1500 gph through a 3/4" pipe restriction. Might get half of that. I think you will still be OK but it would be much better if you had larger or more returns.

 

[Jeff Crawford]

Well I have 2, 1 inch outs or drains and 2 - 3/4 ins ,,, I could swap a 3/4 for the emergency drain or secondary and use one of the 1inch drains as a return in from the Uv with the varios on full speed , what about that?

 

[Jeff Crawford]

Do I need a varios 8?

 

[DCR]

A Varios 8 can handle a little over 7 ft of backpressure at 1500 gph which is reasonable with the proper sized pipe. I don't think a single 1" full siphon will handle 1500 gph assuming it is a typical aquarium on a stand with the sump directly under the tank (4 ft of elevation difference). This will not give you a full back-up overflow. I generally would allow only 300-400 gph for a 3/4" return line. If it is only the final bulkhead connection it can be higher but I think getting 1500 gph with two of them would be a stretch so I still think you are going to be limited. I would run separate 1-1/4" return lines to each 3/4" connection.

For 1500 gph I would want 1-1/2" drains and two 1" returns, but I doubt you need or even want that much flow

I am not sure how big your tank is, but unless it is really large (over 265 gallons), I would use the two 1" drains in a Herbie and run two 1" lines to the 3/4" return bulkheads and reduce down with a reducer bushing at the bulkhead. This should give you 600-900 gph with a Varios 6 pump at full speed. You may want to use a Varios 8 to run at lower speed. Most people on this site seriously overestimate how much flow they are actually getting. I think 3X turnover is more than adequate on most systems and I think you would find the turbulence of 1500 gph on a typical sump unacceptable. Think of it as enough flow to fill a 5 gallon bucket in 12 seconds.

 

[Jeff Crawford]

A Varios 8 can handle a little over 7 ft of backpressure at 1500 gph which is reasonable with the proper sized pipe. I don't think a single 1" full siphon will handle 1500 gph assuming it is a typical aquarium on a stand with the sump directly under the tank (4 ft of elevation difference). This will not give you a full back-up overflow. I generally would allow only 300-400 gph for a 3/4" return line. If it is only the final bulkhead connection it can be higher but I think getting 1500 gph with two of them would be a stretch so I still think you are going to be limited. I would run separate 1-1/4" return lines to each 3/4" connection.

For 1500 gph I would want 1-1/2" drains and two 1" returns, but I doubt you need or even want that much flow

I am not sure how big your tank is, but unless it is really large (over 265 gallons), I would use the two 1" drains in a Herbie and run two 1" lines to the 3/4" return bulkheads and reduce down with a reducer bushing at the bulkhead. This should give you 600-900 gph with a Varios 6 pump at full speed. You may want to use a Varios 8 to run at lower speed. Most people on this site seriously overestimate how much flow they are actually getting. I think 3X turnover is more than adequate on most systems and I think you would find the turbulence of 1500 gph on a typical sump unacceptable. Think of it as enough flow to fill a 5 gallon bucket in 12 seconds.

Agreed, I’m running a 220gal half cylinder, the Uv (pentair 40 watt) needs about 1500gph ,algae control so I ordered a varios 8, and 1/14 inch line to the uv that goes to 1 inch to tank, and reduced again into tbe 3/4 inch bulkheads , the two 1inch drains will be active drains with apex flow sensors , my manifold running gfo, carbon and up to 4 other devices and a second pentair 40w Uv running at low flow pest control about 280gph powere by a varios 6 running into the second 3/4 (in bulkhead) What you think?