new here Help! ...What am I doing wrong? Advice please?

T

trrack2far

Hello folks, my name is Dave an Im already a SWFaholic!

I am finally putting water in my tank tonight for the first time. My problem is matching the return with the drain.

It is EXTREMELY difficult to prevent the water level in the tank or sump from rising or falling. Ive been at it for 4 hours and just now got it equalized and stable (I think). Is it supposed to be this hard? Here is my setup.

37g Tank
HOB Overflow (600 gallons/ Hr) (overkill)
15g DIY Sump/ Fuge
Mag 7 Return in the Sump/ Fuge (overkill)

- I have hard plumped it all with 3/4" PVC.
- I have a ball valve just below the Overflow to control the drain
- I have a ball valve about a 1 1/2 feet above the Mag 7 to control the return.

Here is a link to my sump and plumbing layout (on photobucket)
http://tinyurl.com/363ox6

It seems that if I even THINK about unplugging the pump, or fooling with the Overflow, then I have to start all over again. Am I doing something wrong? Did I overkill too much on the Overflow and the Return Pump.

Did I miss providing enough info? If so, please let me know.

thanks,
dd
 
Couple of random thoughts:

-Mag 7 for a 37 gallon tank is probably overkill...
-Never even EVER put any type of valve on the drain side of your plumbing... BAD mojo! :) You don't want anything restricting the flow of water down. I usually recommend having larger plumbing on the drain side then on the return side for this very reason (I have 1" drain on my main dispaly, and 3/4" return, for example)


I'm a bit out of practice with external overflows, having not used one in ages, but properly set up, you should be able to stop the pump, and resume it and have everything run just fine.

IMHO, I'd take the valve off the drain line, and put it ON the return line, and try throttling the pump back. If this works well, I'd swap that pump out for a smaller one...
 
The Mag 7 is a bit much but the overflow should be able to keep up with it....

You should restrict the flow going in, not coming out as was mentioned. I would also suggest 1" overflow pipe to the sump from the tank. That should allow plenty of flow-through. If your out is more than your in, the tank will reach a balance. If your overflow at that point keeps quiting on you, then you can look at the overflow itself. Most work well, but some need primer pumps. The only one I would use would be a lifereef overflow as they never need priming once they get going.
 
I agree the 1" line will help you immensely, see calculations below:

if the overflow has a 6" or so container for the water level, here are your flow rates:

3/4 drain line: 6.4gal/minute (less than 400 gal / hr)
1" drain line: 11.4gal/minute (more than 600 gal / hr)

It is better to not have the ball valve directly connected to the pump output. Place a T leading to the pump. Have one line with a ball valve go back to the tank. Have the other line go back to the sump. Adjust the ball valve to allow more/less water to the tank. This will reduce the pressure on the pump (pumps like to go full speed, not throttled back).
 
Charlie,

thanks for that information. I will indeed add that T to the return side.
I will put in a 1 inch drain as suggested by everyone.

thank you for the post.

dd
 
Ok, I see one problem you will most likely run into with a 1" drain. the drain will probably operate at maybe 590 GPH. Depending on the lift to getting the water back into the tank, you might hit 450 GPH. what this will do is drain your tank to your overflow level then stop the overflow. you're pump will continue to play catch up. If you dont have thinkgs balanced out and room in your sump, you'll overflow your sump, then pump all the water back into your tank, overflowing that then burning up your return pump. I have almost the same exact plumbing (using 1") and I've already done that and got the saltwater shower to prove it :oops: . Luckily I was right there trying to adjust the flow levels and I saw the pump struggling to keep up. I shut down the drain's ball valve to prevent sump overflow to suddenly have a Tank overflow :oops: :oops: . My 120 is Drilled with 2 drains, and I've never had a problem.
I would go to Harbor freight and pick up a cheap overflow alarm and invest on towels
 
The external overflow will not lose the siphon in this case. There will not be a flood based on the overflow being too strong for the pump. And the pump will be happy running at the full throttle, the water flow rates should be about equal in this case. The only risk of flooding would be losing siphon on the external overflow while the pump still runs (this usually happens if the external overflow does not have proper clearence on the u-tube that keeps both sides under water)..... As Serk stated, do NOT put a ball valve on the drain to the sump!
 
As was mentioned definitely don't put a valve on your drain. Over time the plumbing can gunk up and become clogged enough that your tank might back up and overflow. Also it's possible that a snail or fish could get stuck at the valve causing an overflow. Leaving it wide open and properly sized will help prevent this.

Something else to point out since the thought of "equaling out the drain to the pump" was brought up....


Your drain can only drain as much water as the pump provides it.

So the only thing you should worry about is having a drain that can handle the pumps volume and preferably more to be safe. A proper overflow will not lose suction or stop draining just because you are sending it less water via a smaller pump.
 
Exactly if anything you want to uindersize and only send 400 gph to a 600GPH drain. Now you don't want to be way under like 200 as you might have issues (thjough I doubt it, I'm with Serk here and way to many years removed from overflows to remeber)

Add the T as suggested and bypass enough so you only have 400-500 gph going through the tank. Everything will work perfectly then and as everyone else has said never ever ever restrict your drain line. it's a recipe for a disaster!
 
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