It's a matter of volume.. can you solve this puzzle?

[AmatuerAuer]

Hi All,

I have a 120g DT and a 40b frag tank. The goal is the plumb them together into my Emerald 39 sump. I've attached a diagram below to show how they are set up (I draw like a 1st grader..). I am running the herbie method on both tanks and think that may be where the solution lies.

The puzzle:
The volume of water that would flow into the sump during a power outage would cause a flood. I need to design the system in such a way that the resulting back siphon would not exceed the capacity of the sump.

The return lines are plumbed above the water line so no siphon would come there. It would primarily by via the full siphons which I am trying to find a way to get as close to the water line as possible while remaining silent. The distance between the frag and DT and the sump is 5ft or more as they are run through a wall so the lines themselves can contain a decent amount of water.

Is there a way to add a second holding area, like a tank that would work in conjunction with the sump? I could always drill the Emerald 39 and plumb one in but I am trying to find an alternative.

Thoughts?

Thanks,
AA

 

[jsker]

I would install two of these on your upper tank so that the water does not syphon out to the lower level

 

[TheEngineer]

Can you post pics of the overflow for both tanks?

 

[AmatuerAuer]

I'm not sure I understand your suggestion jsker. Install two what?

Icecool2 I will post pics tonight.

 

[p7willm]

If you have room add a second tank plumbed to to sump. You could use it for a large refugium and it would add the extra space for water when power goes down.

 

[ngvu1]

It's all depending on how much water goes to the sump. Even with the pictures of the over flow boxes of the 2 tanks, I am not sure they can figure out how much water will goes to the drain in case of power outage. I would need the length, depth of the 2 tanks. And the level water drop in 2 tank when power is out. It is all math basically; -)

 

[Glasswalker]

What do you estimate the capacity of the plumbing to be between both tanks? If done right you can minimize the back siphon quantity fairly effectively. But it's a finicky thing I've found. With a Herbie, keeping the height of the emergency and main siphon close so there is little drop, using as small an overflow as possible to minimize overflow capacity, and setting up siphon breaks on your return lines, with a high midpoint so the siphon breaks and water flows back to the DT instead of all of it to the Sump... Combined these things can keep your backflow to the capacity of the plumbing and the depth of overflow from emergency to main siphon point.

Aside from that, check valves (if you feel like trusting them), or p7willm's suggestion is a good one too, expanding the sump with a second plumbed fuge.

 

[TheEngineer]

It's all depending on how much water goes to the sump. Even with the pictures of the over flow boxes of the 2 tanks, I am not sure they can figure out how much water will goes to the drain in case of power outage. I would need the length, depth of the 2 tanks. And the level water drop in 2 tank when power is out. It is all math basically; -)

All you need to know is how much water will drain from the overflow and the size of the tanks, the rest is pretty easy to estimate. A picture of the overflow tells me: is this a standard reef-ready tank, how high is the top of the siphon and how is the drain setup. Figuring out how far down the water will go can be answered by that information unless it is a custom overflow. You don't need to know anything about depth of the tank. If you estimate the water drop conservatively all you need to do is calculate the volume from that water drop for each tank. Same goes for the plumbing.

 

[Rybren]

The easy solution is to run less water in your sump.

 

[TheEngineer]

The easy solution is to run less water in your sump.

The issue is the amount of backflow from the tank when the power is out. If he has a 10g sump, for example, and his tank backflows 11g of water the sump could be empty and he would still have a flood.

 

[AmatuerAuer]

Last night was busy and I didn't remember to take photos. There are three 5ft runs of 1" hard pic plus another 4.5ft of various pieces.

Two of the 5ft runs are full, a full siphon and a return. The third is an emergency overflow which is mostly empty.

The 120g will have roughly 7-8ft of 1" line that will be full plus 7-8ft of return line and the emergency.

In writing this, I think the easiest and best ROI would be to plumb a tank onto the sump. I can drill the acrylic sump easy enough and plumb in a second tank.

just need to think through the heights of the bulkheads leaving the sumo and entering the overflow.

Thanks all,
Chris

 

[Rybren]

The issue is the amount of backflow from the tank when the power is out. If he has a 10g sump, for example, and his tank backflows 11g of water the sump could be empty and he would still have a flood.

Agreed, but from his description, I believe that he has a 39G sump. With proper levels in there, it should be able to handle the backflow.

 

[TheEngineer]

Agreed, but from his description, I believe that he has a 39G sump. With proper levels in there, it should be able to handle the backflow.

Probably right. I'd rather have capacity and retain function when possible. The plumbing alone is going to hold close to 6g. I haven't calculated the drop expected in the tanks.