Plumbing Drain ?

[FranktheTankTx]

Question: If I'm draining (2) tanks into (1) large sump from HOB Overflow boxes - Does the pvc need to increase in size after the point both drain lines meet?

I'm trying to visualize this in my head - and it seems if (2) drains met in 1" pvc there would be a log jam there. But if I increased to 1 1/2" pvc after the "T" Drain - it might would maintain drainage properly.

Understand what I am saying?

 

[Shane Hoffman]

You do not have to increase the size. Where they meet pressure will increase simotaneously with volume creating equal back pressure for both lines back to the HOB overflow. This will cause no problems. Also i am guessing that the length of tubing after they meet leading to sump isnt very long. Which would make it even less of an issue.

 

[FranktheTankTx]

Oh really? Well, I guess to go slightly further into it just to ensure I'm doing it correctly... Tank B is about 5 feet away & will drain somewhat horizontally to the larger sump which has Tank A directly above it.

So Tank B drains somewhat horizontally to a "T" where it meets Tank A draining practically vertically.

You are correct - once they meet, another foot or so to go to hit the sump.

So 1" pvc drain pipe all the way thru?

By doing this, I will ensure that 100% of the drain hits the skimmer section. I will then "T" the return to both tanks & "T" one return line to feed about 75gph to the refugium in the sump.

Everything sound good?

 

[FranktheTankTx]

P.S. What return pump would you suggest (or gph rating) to get 300gph to both Tanks & 75-100gph to refugium in sump?

I have a Quiet One 3000 (780gph), but I'm not certain it will be enough. Maybe a Mag 9.5?

 

[Shane Hoffman]

Yep 1" is perfect. Definately go with the mag. also make sure that horizontal 5 foot stretch of pipe from tank B is slightly down hill. I would say atleast 2 to 3 degrees minimum. Also use spa-flex wherever possible. The pvc is nice looking but the spa flex allows for more sweeping lines instead of straight lines which could allow you to use 45s in place of any 90s and allow everything to flow easier.

 

[Shane Hoffman]

On your return pump dont forget your head loss. The rating should be on the pump (gph loss per foot of head). That quiet one 780gph wont be 780gph once you go up through those pipes.

 

[FranktheTankTx]

Shane - Thanks for the advice. I've got a few feet of spa flex pvc to make a few bends & some 45's to use instead of 90's. Hopefully it will turn out really nice - not my first time to plumb a tank, but it is my first time to plumb (2) tanks into one.

I'll have to run to the LFS tomorrow & pick up a Mag 9.5 - hopefully that is big enough to do the job. I think it will be.

 

[Shane Hoffman]

I think the 9.5 is perfect. If your worried go the next step up and you can throttle it back a bit or increase the amount through your fuge my 50 gph. Also if you get time post some pics......sounds like a cool set up....

 

[Jorober]

Well, the first answer about putting a T onto the drain line is partially correct. There will be equal pressure in each pipe back to the overflows, if a few things are true. First the pipes have to be equal length. Second they have to descend at an equal rate. Third they have to descend from the same height. If not, there will not be an equal pressure in the lines. You would be much better off using a 1.5" T where the lines come together, and finish out with 1.5" line into the sump. That way there is no back pressure. The less back pressure, the better the drainage. You need to remember one major rule... You ALWAYS need more drainage than your pump returns. That way you'll never overflow your tanks.

 

[Jorober]

Sorry, I didn't finish my thought about inequal pressure. If there is not equal back pressure, you will probably overflow whichever tank is lower to the ground, or closer to the sump.

 

[FranktheTankTx]

Oh boy, conflicting answers. Yes, the tanks are of different heights. And obviously, since one is 5 feet away, it is draining from a further distance than the other tank - which drains vertically to the sump.

This was my original fear - which caused me to consider going 1.5" from the "T" to the sump.

I'll be controlling the return lines with ball valves - so I can control flow going back into the tanks.

UPDATE: Actually, I think 1.25" would be fine at the "T" to the sump. I think it would drain fine - and probably be easier to plumb.

I think I'll do this to be on the safe side - it certainly won't hurt anything.

 

[Shane Hoffman]

Frank,

You are okay either way. Like I said, especially if the length after the T to the sump is short. You verified it was. I have this exact setup with a frag tank that has 7 feet of pipe running from my tank B.

My overflow boxes are both rated for 300gph which I assume based on the size of the tank in your description signature.....your using the same??????

If you are using un equal size overflows or have some how increased their volume you will want to go with a increased T size.

I guess we need more info....but due to this being a such a simple fix to be sure just go with the larger line after the T.....

 

[FranktheTankTx]

Thanks Shane - I bought some 1 - 1.25" fittings & a 1.25" T to increase it .25". It will definitely work now... thanks for your help!

 

[Shane Hoffman]

Did you p/u that mag pump......???

 

[FranktheTankTx]

Nope, bought a Quiet One 5000. I've used Quiet One pumps for 4 years without a problem - they didn't have a Mag bigger than a 7... but had Quiet One 5000 & 6000. I should be good.