Help me make a sump/refugium for this situation!

pegasus

Well-Known Member
Weird. I wonder what is wrong with mine.

I will build another one using 3/4" tubing for the 40g I'm upgrading my other tank to. As far as this one goes I said screw it and put an eshopps pf nano on it. I had already bought it but planned to return it. So much about that.
If it's built right, you should be able to get about 300 GPH from a single overflow, which is 7.5 times turnover per hour in a 40 gallon tank. Just be sure to test it (two 5 gallon buckets of tap water mocked up at the tank/sump height works great) before installing it to be sure of the flow rate, and then adjust the return pump to match the flow.
 

pegasus

Well-Known Member
I'd like to see it... lol!

Even though these overflows are not supposed to break siphon, it can happen. I'm seriously considering removing the check valve and installing an aqua lifter pump to make sure all the air gets removed... and stays removed.
 
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beaslbob

Well-Known Member
I'd like to see it... lol!

Even though these overflows are not supposed to break siphon, it can happen. I'm seriously considering removing the check valve and installing an aqua lifter pump to make sure all the air gets removed... and stays removed.
Another option is to setup up a venturi on the return pump connected to the hob part. To suck out usually a little water, an occasional air bubble, and the air to reestablish siphon when the siphon was lost.


my .02
 

pegasus

Well-Known Member
Another option is to setup up a venturi on the return pump connected to the hob part. To suck out usually a little water, an occasional air bubble, and the air to reestablish siphon when the siphon was lost.


my .02
If you have an HOB on your tank, it's an excellent option. Unfortunately, my return pump is in the fuge about 8' below and about 12' feet from the tank. I have 5 pumps crammed into the return chamber, so there's absolutely no room to install a venturi. I believe a $20 lifter pump is my best option... but the venturi is a really good idea for those with HOB's.
 

seecrabrun

Active Member
I'd like to see it... lol!

Even though these overflows are not supposed to break siphon, it can happen. I'm seriously considering removing the check valve and installing an aqua lifter pump to make sure all the air gets removed... and stays removed.
I was thinking of doing the exact same thing.
 

beaslbob

Well-Known Member
Understand.

another option is to do the same thing only on a power head. Which actually would be better because the hob and power head is at the same height and over the tank.
 

bang guy

Moderator
Caution with the powerhead. In a power outage it can start a reverse siphon and drain the tank all the way down to the powerhead nozzle and flood the sump.
 

beaslbob

Well-Known Member
Bang
Caution with the power head. In a power outage it can start a reverse siphon and drain the tank all the way down to the power head nozzle and flood the sump.
I must be missing something here but then that's the way I learn.
I don't understand how a power head with it's intake and outlet both in tank and at most 2" below the top of the hob overflow can do that?

Now that is a very good point for the return plumbing and why I try to have the outlet of the return lines slightly above the display water level. And anti siphon holes and the like also.
 

bang guy

Moderator
Bang

I must be missing something here but then that's the way I learn.
I don't understand how a power head with it's intake and outlet both in tank and at most 2" below the top of the hob overflow can do that?

Now that is a very good point for the return plumbing and why I try to have the outlet of the return lines slightly above the display water level. And anti siphon holes and the like also.
Many external overflows do not lose siphon when the return pump stops. Since the siphon is still active it can pull water through the venture tubing for as long as the intake and outlet of the powerhead are submerged. Once the water level in the tank drops below the powerhead the venture will suck air and break the siphon.

On the two-box overflows the siphon will stop once the tank water level matches the water level of the outside box. This could still be many gallons of water.

If your overflow actually loses siphon when the return pump stops then it's not going to be an issue.
 
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beaslbob

Well-Known Member
Many external overflows do not lose siphon when the return pump stops. Since the siphon is still active it can pull water through the venture tubing for as long as the intake and outlet of the powerhead are submerged. Once the water level in the tank drops below the powerhead the venture will suck air and break the siphon.

On the two-box overflows the siphon will stop once the tank water level matches the water level of the outside box. This could still be many gallons of water.

If your overflow actually loses siphon when the return pump stops then it's not going to be an issue.
That's what I thought.

The venturi to the power head is just a replacement for the aqua lifter type setup.

It should suck out air bubbles preventing buildups in the siphon and well as sucking out air if siphon was lost during the power outage. Reestablishing the siphon and normal operation.

Diy pvc designs work under the same principals as the two box. Only the water trap external to the tank is a pvc pipe not a box.

So I guess the same concerns would apply there.

my .02
 

pegasus

Well-Known Member
why so many pumps?
1: 125 tank, 2: 40B tank, 3: RDSB, 4: GFO/carbon reactor, 5: UV sterilizer.

Caution with the powerhead. In a power outage it can start a reverse siphon and drain the tank all the way down to the powerhead nozzle and flood the sump.
I sold 4 practically new Koralia Evolution 1150 pumps for that reason. Pumps using A/C current are notorious for starting backwards. Fortunately, all 8 of my powerheads (in 2 tanks) are D/C powered, so they always start in the right direction... ;)
 

bang guy

Moderator
Any thoughts of going to a single large external pump to replace the sump full? Three phase pumps never start backwards.
 

pegasus

Well-Known Member
Any thoughts of going to a single large external pump to replace the sump full? Three phase pumps never start backwards.
I suppose once all the plumbing is done and everything is dialed in with an external pump, it would make life a little easier. Getting there would be the challenge. I bought specific sized pumps as I knew what the flow would be for each system it provided flow to. Splitting a single pump into 5 outlets and tweaking the flow for each tank would be a bit difficult to do, since the refugium is in the basement and the tanks are upstairs. The RDSB, GFO, and UV wouldn't be bad since they're in very close proximity to the fuge. I'm sure it would also reduce the heat produced by those 5 pumps... though my tanks never get above 81F.

I'll have to think about it for a while... I have reservations about going single-pump mode. Other than the cost of an adequate sized pump, gang valves, unions, pipe, etc., the thought of having a single pump suffer a failure could amount to big trouble... fast.

PS: Don't think they'll be making three phase powerheads or wavemakers any time soon... lol!!! :p
 
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