can you Tee the intake of an external return pump

[johns]

Was wondering if it was ok to Tee off the intake of an external return pump, say something like a Velocity T3 or T4 pump? Was considering so that water could be pulled from 2 different tanks, and returned to the main tank.

[lakee911]

If you put a tee on your suction to each of the tanks, you'd effectively join the two tanks. Are they at the same level? If not, you could over flow the lower one. If you're relying on a siphon to maintain suction (ie pull it up over the tank and then and into the pump), then priming might be difficult and it might lose its prime if one pulls down too fast. The hydrolics really depend on your setup. I would use two seperate pumps though.

[sarduci]

It'll be hard to balance the intake from both to be the same without using ball valves, but you can do it.

[johns]

The way I'm thinking, the water level of both tanks would be about the same. For instance, say I was going to have 2 40G breeders, and use 1 as a fuge and 1 as a frag tank. Could I have a small return section baffled off in both tanks, and then use an external pump to pull the water from both tanks as the intake.

[BLockamon]

Are you running a common sump? If so, you can control the amount of water drained from each tank by controlling the return flow to each tank.

If not, then you'll need valves on the two inlet lines (and probably the two outlet lines as well) to balance flow.

[schro]

Why could you not just have your 'fuge' overflow into the return section of your frag tank?
It's simple! Any additional complexity could potentially cause a problem.
Balancing with ball valves would be near impossible to get right, even a minor differnce in the draw from the 2 seperate tanks would result in one draining faster. It would require constant monitoring.

I've been designing the plumbing for my new tank and have done a lot of research, and I have not seen anyone do what you are asking... I'm not saying that it can't be done, but the fact that it hasn't (or has been rarely) leads me to conclude that it's not a good idea... use a single draw, simple is GOOD!

[schro]

Excuse me (sheepishly said)
I've been rethinking what I just posted.
if the water level in the baffled return section in tank 'A' return dropped below the water level in the baffled section of tank 'B' return, then the water pressure from tank 'B' return would be higher, and hence the pump would draw more from that side until the levels were approximately equal. This is of course contingent on the 2 tanks being placed at the same level, and the tee leading to the pump being roughly equidistant from the 2 tanks.
If that is the orientation that you had in mind it would work without ball valves.

[ifoundnemo]

just be careful if you use any kind of valve...if its not open all the way it could cause air bubbles to form...if too many get in to the pump you will lose your prime

[prugs]

John,
You want the T on the outlet side of the pump. Split the flow to the frag tank & main tank. Put a ball valve on the frag tank press line to control/restrict the flow to that tank. The main tank will get the rest of the water.
Both the frag tank & the main tank will drain to the sump/skimmer area.
I like that idea better.

[johns]

Yeah, I did decide that the T-ed intake was too much trouble.

I could either put the return pump in the sump and split the outlet of the return pump to the frag tank as you say here, or I could connect the sump to the frag tank via a bulkhead and put the final return chamber and return pump in the frag tank, instead of in the sump.

I dont know which is a better choice, quite honestly. But with the first choice, I may need to get another return pump if the current one I have may not be enough to run both the main tank and feed the frag tank. With the second choice I may be able to do the whole thing with my current return pump. Any other opinions?

[prugs]

With both tanks draining into the skimmer compartment & then thru the fuge, the return to tank water should be cleaner.

[johns]

With both tanks draining into the skimmer compartment & then thru the fuge, the return to tank water should be cleaner.

Not sure that I really follow the difference. With the second scenario, the main tank drains down to skimmer first and then through fuge and out to frag tank. So that water has been 'cleaned' as well before hitting the frag tank and going back to the display.

With the first scenario, I'm also not sure I follow how to get the frag tank to 'drain ' back to the skimmer compartment. Remember that the frag tank will most likely be shallower than the sump, or perhaps the same height at best. I dont think I want to raise the frag tank up any higher either, because there wont be much room under the stand for that. I expect those 2 tanks will be sitting at about the same level.

[prugs]

With the first scenario, I'm also not sure I follow how to get the frag tank to 'drain ' back to the skimmer compartment. Remember that the frag tank will most likely be shallower than the sump, or perhaps the same height at best. I dont think I want to raise the frag tank up any higher either, because there wont be much room under the stand for that. I expect those 2 tanks will be sitting at about the same level.

Yes without raising the frag tank, draining the sump water to the frag tank is your only option. Then you just need the return pump on the frag tank, & no T's.
The only advantage to the frag tank water going into the skimmer compartment, is the skimmed/fuge "very clean" water will go directly to your display tank.
With the fuge/skimmer water draining to the frag tank, & pumping frag water to the diplay. The frag tank water is "not as clean", so you are pumping "not as clean" frag tank water to your display tank.

[johns]

Yes without raising the frag tank, draining the sump water to the frag tank is your only option. Then you just need the return pump on the frag tank, & no T's.
The only advantage to the frag tank water going into the skimmer compartment, is the skimmed/fuge "very clean" water will go directly to your display tank.

I do see the possible advantage in the scenario you are suggesting - it's like you are sending a portion of the water through the skimmer and fuge twice before heading to the display. But I think it might be minimal, because the skimmer can only 'clean' a limited volume of water in relation to the total amount draining to that compartment anyway. But in the scenario I am suggesting, the water should get skimmed/fuged first, then head to the frag tank (where is theoretically shouldn't get a whole lot 'dirtier') and then up to the display.

I am just trying to do this as simply as possible, and hopefully with just my single existing return pump (Eheim 1262). But I need to know that it at least makes sense and should work, because it requires drilling a couple tanks and the stand.

So to be clear, I am thinking about a 75G sump. The water level will be kept approx 12 inches thoughout, except for the fuge. One of 2 drains would be T-ed off so that a low volume can run to the fuge first. So the sump will look like, from left to right:

fuge (kept at slightly higher water level, say 16 inches)
single baffle
skimmer & drains
baffles
bulkhead

now the water needs to travel through the bulkhead to another tank, maybe a 40G breeder:

bulkhead
frag area
baffles (bubble trap)
return pump goes back to display

Here's a couple questions I have right now:

Does this make sense?
What size bulkhead do I need to make sure the water between tanks doesn't get overpowered by the return pump?
Do I need a baffle right after the bulkhead in the frag tank to keep the water from rushing in too forcefully into that frag area?

[prugs]

What size bulkhead do I need to make sure the water between tanks doesn't get overpowered by the return pump?

I think 1-1/2" should be good.




Do I need a baffle right after the bulkhead in the frag tank to keep the water from rushing in too forcefully into that frag area?

Have the bulkhead in the corner, so that it causes a swirling effect in the tank. Then the return pump could be in the corner adjacent to the bulkhead.
No baffle required.

[johns]

Have the bulkhead in the corner, so that it causes a swirling effect in the tank. Then the return pump could be in the corner adjacent to the bulkhead.
No baffle required.

You dont think I need to worry about bubbles? The pump might be returning 600-700 gph to the display. So all that force will also go through the bulkhead into the frag tank too.

[prugs]

Maybe I misunderstood.
I thought you had some baffles in the sump prior to the water going thru the bulkhead to the frag tank.

[johns]

I'm was thinking of a single baffle between the fuge and drain/skimmer just to section the fuge off at a higher level. And then a set of baffles between the drain/skimmer and the sump bulkhead to act as a bubble trap to minimize bubbles entering the frag tank.

I was just being redundant. I was thinking that 600-700 gph entering the frag tank forcefully might stir up more bubbles that could possibly go to the return pump. But the bulkhead will be towards the bottom of the tank, I guess. Maybe I wont really get more bubbles from this part? Never tried anything like that, so I dont know what to expect.

But wait, I should probably assume I might get debris, rocks, etc from frags (or maybe a small fish kept in the frag area) that might get sucked into the return pump with no baffle before it, so I should maybe still consider it.