Drain flow control

M

M3AN ONE

Reefing newb
Location
Long Island
The water draining down from my main tank into my first sump chamber is to violent. I have a union ball valve attached to ea h drain. If I use them to control the flow of water into the sum will that cause my main tank to overflow? Also is it normal to have the drain pipes extend a little beneath the water line or should I have cut the PVC pipes above the water line?
 
You should never close down on your overflow lines (except in specific overflow designs) as the overflow rate is regulated by the return pump flowrate, and thus will overflow the tank..... If you go to Reefcentral there are many silent overflow designs you can search. If you have overflow noise one thing that can work well is to direct the overflow water into a horizontal direction under the water level than have it go into the smaller side of a reducing "T" with the upper opening (bigger than the overflow line) extended several inches above the water level and the lower end (bigger than the overflow line) extended several inches down into the waterr. This allows a slowdown area and bubble release. I generally use this design....There are also many designs for the tank end of the overflow line (Durso, Herbie, etc...) look on RC...
 
Your drain should end beneath the water.
If it's draining too much too fast, yes you can close down the ball valve a bit. If this causes the water to rise in your tank too high, you can close down the valve that's after your return pump, to cut back on the return pump's flow.
 
Dont use a ball valve, cant control your flow easily. Use a gate valve or use a larger diameter pipe that is capped on one end. Then let it boil from there and that will stop the vortex in the water
 
He already has a ball valve so it's fine. You're right that gate valves are easier to adjust but ball valves work ok and are much easier to shut off completely in a hurry.
 
M3AN ONE said:
If I turn down my ball valve to my return wont that damage my pump?
Click to expand...

+1 what Northstar said.
This is why i said the valve AFTER your pump. You can turn that down practically half way if you need to without damaging your pump. But if you need to turn it down that much, you should probably look for a smaller pump.

As to the flow in your sump, you should only have about 3-4x turnover rate through your sump. Most of your flow should come from power heads inside your tank. If your water is flowing over your baffles it sounds like you are trying to push way more water through the sump than it was designed for.
 
You need to get a pump with an output that is close to the rating on your overflows. This way your overflows will be able to handle the water moved by your return pump

For example, if you have two overflows rated at 600 GPH each, you would want a return pump rated for approximately 1200 gph AFTER estimating head loss
 
Sorry, but I don't agree with Northstar....

The pump doesn't have to match the overflow rate but if you think about it all the overflows are, is overflows...You don't want a pump that pushes too close to the overflow rate because any fouling or blockage of the overflow will make the tank overflow...the overflows will only drain the amount of water your pump is pushing up to the tank....the flow into the tank will all go down the drain with the level controlled by the overflow wall...The danger is when you start messing with the overflow drains by throttling down on them...then when just the right little hunk of algae, wasted food or snail will slow it just that critical amount more and you will be explaining the flooded living room to the wife...

Your real goal for return pump rating should be matching the flowrate of your skimmer pump...that way you will have a good turnover of the water through the skimmer...

If your pump pushes the full amount of water that the overflows are rated at then you are right on the edge of flooding....
 
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Actually i agree with both. Alot of pumps are rated for max head pressure of 4ft. So northstar isnt far off. From sump to dt, on a stand application, you would want to run at max gph, or your flow rate will be 50%. If your choice is a postive displacement oump, ie an in line pump i would agree with michreef. I am running from my basement with 21f of head pressure and the only pump i found to work is the reeflo blowhole pump. If your overflowing your baffles, i dont think your sump is gonna work or reduce your flow. If you flip your water 3-4 times per hrx that is plenty of filtration.
 
MitchReef said:
Sorry, but I don't agree with Northstar....

The pump doesn't have to match the overflow rate but if you think about it all the overflows are, is overflows...You don't want a pump that pushes too close to the overflow rate because any fouling or blockage of the overflow will make the tank overflow...the overflows will only drain the amount of water your pump is pushing up to the tank....the flow into the tank will all go down the drain with the level controlled by the overflow wall...The danger is when you start messing with the overflow drains by throttling down on them...then when just the right little hunk of algae, wasted food or snail will slow it just that critical amount more and you will be explaining the flooded living room to the wife...
Click to expand...

That's a risk you always run with having an overflow. The flow rate wouldn't matter, what if the chunk of algae or snail is big enough to slow your flow rate enough to cause hours to overflow. That's just something that may happen to any of us and a risk we take.

MitchReef said:
Your real goal for return pump rating should be matching the flowrate of your skimmer pump...that way you will have a good turnover of the water through the skimmer...

If your pump pushes the full amount of water that the overflows are rated at then you are right on the edge of flooding....
Click to expand...

Why would this be your goal for the return pump? It doesn't ensure any more water makes it into your skimmer then having a faster flow. And just having the water flowing isn't ensuring all of that water is getting into your skimmer. It's still just whatever water is in front of the skimmer pump inlet that's getting sucked in.
 
I would argue that you actually want your return pump to be rated a little higher than your overflow to account for head loss as it pumps water back up to your tank. If your sump is located in the stand then you will have some head loss, if its located in your basement then it will lose a lot more pressure on its return trip to your tank. In my case, my return pump is rated around 600 gph and my overflow is rated around 500 gph. I can leave both fully open and neither my sump or DT overflows, but my flow does slow down if I don't clean the overflow box regularly. I have a ball valve on my return line to help match flow if needed, though haven't had to use it in quite a while. You can also put a float switch on your return pump to shut the pump off if the flow to your overflow slows down or (in my case since I have a hang on back overflow) if the siphon breaks. One word of caution with the float switch - try to find one that once it shuts off won't turn back on until you manually reset it. I have one that just turns on and off as water in the return line drains back into the sump. I need to find a quiet true check valve to add right at the base of my return line to prevent backflow when the float switch is activated.
 
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Turned return pump down and everything is much better now. The water level in my return section went up about an Inch as well as the water in my first chamber became less violent and dropped about a half inch.
 
I'm just referring to experience and the teachings of Sprung in his talks at Macna, etc....I'm not sure why anybody would want their entire overflow racing through their sump....My thought was alway slow through the sump, fast in the tank....I guess by this thinking I should probably be running 2 or 3 1100GPH return pumps in my 120 with dual MegaFlow overflows? Each is rated at about 1400GPH...

I dunno, I'm just a noob at this stuff....Just seems taht this discussion is suggesting pushing water through the tank at a rate equivalent to its extreme flow limit...I always thought of it the other way around, which is that the flow of the pump determines it all, with the overflow rating being where the safety margin lives....
 
The T works well I installed one for my set up and works great for flow control. Does the water in your overflow fall all the way down to the bottom of the tank if so you might consider installing a standpipe in your overflow it will cut down on the noise of the water falling all the way down to the bottom.
 
JohnVH said:
The T works well I installed one for my set up and works great for flow control. Does the water in your overflow fall all the way down to the bottom of the tank if so you might consider installing a standpipe in your overflow it will cut down on the noise of the water falling all the way down to the bottom.
Click to expand...
Make sure you install a gate valve, the noise of the return water racing in the pipe is very annoying too. This works also if you are running large volumns, it keeps the water from not spashing all over when exiting the overflow
 
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