Drains size for 540 Gallon?

[ElectricBlueSeanBurch]

I'm gonna flow 3592 GPH through the sump with 2 Max-Flow 2400's. So 1.5 inch drains would work, but that'd be at the high end of their capacity. 2 inch drains would be the way to go, then..

I have ~3000gph running through 3x1" drains. You are planning on running 4x1.5" drains that will handle almost twice what you are planning. You could have 2 drains clog and it would easily handle the flow once one grabbed full siphon. Believe what you want but I can tell you for a fact that 1.5" drains would work perfectly for you.

 

[DB junkie]

Why not go as big as possible?

Down the road if you go to sell the tank in my eyes this would make it worth more.

Change what you keep, and maybe you'll need more flow.....

Lots easier to shrink to your application now then have to cut later......

 

[ragin_cajun]

That's what I'm thinking. If there's ANY chance that I MIGHT need more flow later, it'd be nice to have 2 drains. What if I get bigger pumps cause the fish grow. What if I hit the lottery and decide to go reef? Better someone else drill now than me drill later.


Sent from my iPhone using MonsterAquariaNetwork app

 

[swedeboy78]

Two 1.5" drains will be fine for your dual Laguna 2400s. Exactly what I run on my 600 with 5' head and drains could handle much more in my opinion.


Sent from my iPhone using MonsterAquariaNetwork app

 

[ElectricBlueSeanBurch]

Two 1.5" drains will be fine for your dual Laguna 2400s. Exactly what I run on my 600 with 5' head and drains could handle much more in my opinion.


Sent from my iPhone using MonsterAquariaNetwork app

Op please note that this post confirms that 2x1.5" drains easily handles dual Laguna 2400's. So your 4x1.5" drains could easily handily 4 of the 2400's do you honestly ever think you will ever need more flow than ~7500gph? If so go 2" completely up to you...

 

[aldiaz33]

It looks like he's planning on a running a herbie system in each of his two overflows, so only two of the four drains would be in use and the other two would be emergency back-ups. But I agree that two 1.5" drains (under full siphon) should be plenty.

This calculator has the info you are looking for. According to it, a 1.5" drain with 24" of head can handle up to 3,750GPH each. So in theory you can push 7,500 through two 1.5" drains. Keep in mind that is assuming full siphon (no air in the system) and no horizontal runs (just a straight vertical drop to your sump). Any air in the system and/or horizontal runs will reduce flow.

Just for the heck of it, I ran the numbers using 2" pipe and with the same 24" of head, a 2" pipe can handle up to 6,667GPH under full siphon. Again, that's assuming no horizontal runs so that number is probably higher than what most real world applications would achieve since we all typically have at least a small amount of horizontal pipe, elbows, etc.

So you will be good using 1.5" at full siphon, but you might be pushing it if you were to run Durso standpipes where air is being introduced to the drain. If you were running dursos, I would probably go with 2" just to be safe.

Side note: I've read that you should never consolidate two drain lines from a Herbie system so that one pipe drains into your sump. You probably weren't planning on doing it that way, but just thought I would throw that out there to prevent any headaches; I read that it makes it really difficult to calibrate the system if you use a T to combine the drains. If you are running two overflow boxes, each Herbie should be run entirely independent of the other.

Side note#2: The flow limitation in my tank isn't the pipe/bulkhead size, but my overflow teeth. I found that if I tried to push more than 4,500GPH, my overflow teeth would become overwhelmed. In other words, water being pumped into the tank was not able to move past the overflow teeth to the drains quickly enough and the water level in my display would rise and water would spill onto the floor if I didn't valve the pump back. It's an easy fix (just knock out some overflow teeth), but just thought I would throw that out there.

Looking forward to seeing pix of your setup. Sounds like an awesome tank.

 

[ragin_cajun]

I agree that 2 1.5 lines at full siphon will easily drain the 3592 GPH input from the pumps. What I'm getting at is this. I haven't been exactly clear. I want to know if a pair of 1.5 inch, or 2 inch lines will drain the 3592 GPH input in an emergency situation. Say I tie the 2 drains together, like JC1119 did in his journal, and one day when I'm outta town the gate valve just clogs totally. Water rises in the overflow, emergency drains kick in, but I can't assume that water will go down those emergency drains at full siphon. THAT'S the drain capacity I'm trying to figure out. And it's hard because it's not laminar flow at full siphon.

I want to know that the 2 emergency drains can drain this tank, suckin in air, at 3600 GPH. Talking to some other aquarists around town, and my LFS, I'm finding out that A LOT of people don't even worry about a backup drain. LFS says they very often install a tank with a 1" drain, a 3/4 return, use Durso with an air opening to "help with the noise", and they don't worry about having an emergency drain at all. I gotta have a backup drain, and if I'm gonna have redundant drains, why not be sure that the backup drains can drain the pump output under the worst of conditions--turbulent flow, no siphon for the first few minutes if ever, both primary herbie/siphon drains totally clogged.

 

[ElectricBlueSeanBurch]

I agree that 2 1.5 lines at full siphon will easily drain the 3592 GPH input from the pumps. What I'm getting at is this. I haven't been exactly clear. I want to know if a pair of 1.5 inch, or 2 inch lines will drain the 3592 GPH input in an emergency situation. Say I tie the 2 drains together, like JC1119 did in his journal, and one day when I'm outta town the gate valve just clogs totally. Water rises in the overflow, emergency drains kick in, but I can't assume that water will go down those emergency drains at full siphon. THAT'S the drain capacity I'm trying to figure out. And it's hard because it's not laminar flow at full siphon.

I want to know that the 2 emergency drains can drain this tank, suckin in air, at 3600 GPH. Talking to some other aquarists around town, and my LFS, I'm finding out that A LOT of people don't even worry about a backup drain. LFS says they very often install a tank with a 1" drain, a 3/4 return, use Durso with an air opening to "help with the noise", and they don't worry about having an emergency drain at all. I gotta have a backup drain, and if I'm gonna have redundant drains, why not be sure that the backup drains can drain the pump output under the worst of conditions--turbulent flow, no siphon for the first few minutes if ever, both primary herbie/siphon drains totally clogged.

Your question is can 2x1.5" drains handle 2x2400 Laguna pumps has been answered in the post I quoted earlier. Do you have any more questions?

 

[aldiaz33]

It sounds like going with 2" emergency drains will help you sleep better at night. In the scenario you describe, if you are not sure your emergency drains will achieve full siphon, going with 2" emergency drains would be better than 1.5".

Just be sure that your overflow chambers have enough room to accommodate 2" bulkheads...they are pretty huge.

Having said that, the likelihood of a drain becoming completely clogged is tiny...and of both becoming totally clogged simultaneously is like winning the lottery (pretty much not going to happen). Something would have to come in from above the tank, since the overflow teeth are going to catch anything the would be large enough to plug a drain.

If you haven't already bought your bulkheads, I really like the schedule 80 bulkheads sold here.

 

[ElectricBlueSeanBurch]

This is getting a tad crazy. Why would you do 1.5" mains and 2" emergency's? Why wouldn't you just do it the other way around? Besides if you have quality overflow boxes and proper drain setups how could 2 separate 2" drains clog? I can't stress these points enough:

3x1" drains can handle ~3000gph without full siphon
2x1.5" drains can easily handle 2x2400 Laguna pumps
2x2" drains can handle any logical pump(s) you want to use.
A proper herbie setup on your tank with 2x1.5" main drains and 2x1.5" emergency drains would be overkill, silent, bulletproof and can handle 10x the flow you would ever need.