DIY PVC Overflow - submerged

[mannmachine]

Hi,
I have a 90 gallon tank with DIY sump filter. (DIY PVC Overflow without box and trickle tower box in sump)
My Overflow pipe is 1" schedule 20 PVC pipe and my pump is rated 440 GPH (without considering height and bends). When I run the pump, the overflow opening is completely submerged under water. There is about 1" of water height above the opening of the overflow pipe. Is that normal?

I'm planning to put another overflow soon. But so far, it has been working fine except for the doubt listed above.

 

[Flaxon-Waxon]

I'm following. I dont have all the answers but can speculate. Any pics to post?

 

[mannmachine]

Thank you Benamayer for your reply.
I'll take the pic tonight and post it.
Thank you

 

[Flaxon-Waxon]

I don't believe it's an issue. How is your drain line plumbed? Is there a valve installed or does it go straight down? Also, do you have enough room in your sump to hold all the water above the drain in case your pump stops for any reason?

 

[mannmachine]

There is no valve. It goes straight down. I'll take a picture tonight to go give an idea.
Yes, there is enough space in the sump to hold water if the pump stops. Tested 2 time with real power outage.
Thank you for your concern.
I appreciate.

 

[Flaxon-Waxon]

I'd like to see pics but I really don't think it's an issue. There is a calculator that figures out how much space that you need in your sump in case of power failure, and 1 of the questions is how high above the drain inlet does the water sit. Let me ask you this... When the power went out, your sump filled up, what happened when you turned the pump back on? Did the water just drain out of the sump until it got to its normal level and the water level in the main tank slowly filled to above the drain? I'm asking because I don't know how the machanics of it works...! Thanks...

 

[mannmachine]

Yes, that's what is happening...When I turn my pump on, water slowly raises in the tank and then the overflow siphon kicks in. Water level continues to rise above the overflow line until it reaches about an inch.
Can you send me the link to the calculator?
Thank you

 

[Flaxon-Waxon]

Sounds normal... Give me a few mins I need to find the link, it's hidden in a website somewhere lol

 

[Flaxon-Waxon]

Heres the Calculator:

http://reefcentral.com/calc/sump.php

Also, check out this write-up on sumps this link came from, some of the best info out there IMO...

http://www.thereeftank.com/forums/faq.php?faq=sump_articles

 

[mannmachine]

Hi Benamayer,
Your links gave a very good insight of overflow.
Thank you.

I've attached the pictures.
Let me know what you think

Thank you for all your help

 

[Flaxon-Waxon]

If you think about how an overflow works, if your pump is putting 400 gph through (400/60 mins = 6.67 gallons a minute) , it will naturally raise the water level above the drain... All that water has to get funneled into a 1" tube.

It looks ok to me, but maybe someone with more DIY overflow experience can help out from here?

 

[Robert_ellis]

The only way to reduce how much water is over the pipe is to increase the pipe size. Remember gravity wont flow as fast as pressured unless you have that head pressure which is the 1" above the pipe. If you put a larger return pump it would go even higher or if you put a smaller it would go lower. Bigger overflow pipe= lower water level... Smaller overflow pipe= higher water level.

Hope this helps.

 

[mannmachine]

Thank you Robert.
I'm following what you are trying to say.
I kind of lowered the overflow level so that the water level is within acceptable limit below the tank top.
Planning to put another overflow soon.