Plumbing external pump

[WhatsReef]

I got myself a Varios 2 for my Fusion 40 because I'm nuts. I was going to run it externally from just behind the tank. There's no instruction booklet but It looks like they're pushing me toward 1" ID for the intake and 3/4" ID for the outtake based on the adapters included.

 

I was going to do all barbed connections with flexible tubing. Basically a hose running into the bottom of the central chamber, then a 3/4" ID hose that splits into 1/2" ID and feeds the 2 nozzles. I haven't pulled out and examined the current tubing yet, but I'm guessing I can feed the 3/4" tube right into the splitter that came with the tank.

 

1. Am I wrong to use all flex tubing and barbed connections - is this a bad idea for any reason. I was going to really work them on deep and clamp them down with those miniature versions of the things you use to attached flexible ducting to metal ducting just for good measure.

 

2. Where can I find good flexible tubing at this large of diameter. The flex tubing they make for computer cooling systems looks dope and I wish I could get something like that in 3/4" ID and 1" ID but it seems to only go up to 1/2". I can get away with the braided 3/4" tubing to feed the returns I think, but I don't want super stiff 1" tubing as it will run down into the AIO chamber. I guess if I have to use stiff 1" tube I can use a U-shaped connector or 2 x 90 degree elbows to run it around the back glass straight up and down, but if there was a high-grade flexible tubing that would be ideal.

 

3. Any other suggestions would be great, never hooked up an external water pump before

 

Thanks!

 

 

[seabass]

If it's truly going to be external, then you'll need a bulkhead to connect plumbing to any wet wall.  I got to be honest, I'm not fully following your plan.  That doesn't mean that it's wrong, just that I'm not visualizing it.

 

Yeah, you are right, tubing gets pretty stiff beyond 3/4" ID (really beyond 1/2").  Braided flex tubing can be straightened by submerging it in very hot water.  IDK, that might help a little.

 

[WhatsReef]

I mean external as the opposite of submerged. It doesn't fit in the return pump chamber - was just going to have it sitting on the table behind the tank with an intake and outtake tube going into the tank... so just running a 1" tube into the bottom of the return pump chamber (with a screen on it to block large objects) to suck the water out, then the 3/4" tubing runs back to the tank and connects to the 2 return nozzles that are pre-installed in the tank. Make sense?

 

I guess if I gotta use stiff tubing I can use some 90 degree fittings to avoid too much bending. Would be nice if there was something really flexible... maybe just not the type of product with wide enough appeal to produce...

[seabass]

Alright, you'll need a 1" bulkhead on the bottom of the return chamber to connect your plumbing to the pump.  If the output of the pump is going up over the walls, then a second bulkhead isn't required.

[Beer]

Spa-flex might be what you are looking for. RV potable water hose is extremely flexible, but I don’t think that it is strong enough for what you are trying to acomplish.

 

Aquarium pumps aren’t designed for a high suction head, they need to to have the water level higher than the input to not cavitate and to actually pump water. They need water pressure on the input to push water, they don’t pull a strong suction. You can overheat the pump and shorten the life as it is working harder than intended and it doesn’t have as efficient cooling as it would sitting in the water. Also verify that the pump is suitable for running out of water. Not all pumps that have intake fittings are rated for running externally.

 

 

That being said, I am doing something similar with mine. I am running 1 1/2” rigid PVC for the intake, set up so I can pre-fill the plumbing and suck the air out of the plumbing. The pump needs to sit below the water level, below the tank would be better. Think of it being set up so that the water is siphoning into the intake, not the pump pulling the water up over the edge of the aquarium. With the pump off, water should stay in the intake tubing/piping.

[WhatsReef]

37 minutes ago, Beer said:

Spa-flex might be what you are looking for. RV potable water hose is extremely flexible, but I don’t think that it is strong enough for what you are trying to acomplish.

 

Aquarium pumps aren’t designed for a high suction head, they need to to have the water level higher than the input to not cavitate and to actually pump water. They need water pressure on the input to push water, they don’t pull a strong suction. You can overheat the pump and shorten the life as it is working harder than intended and it doesn’t have as efficient cooling as it would sitting in the water. Also verify that the pump is suitable for running out of water. Not all pumps that have intake fittings are rated for running externally.

 

  

That being said, I am doing something similar with mine. I am running 1 1/2” rigid PVC for the intake, set up so I can pre-fill the plumbing and suck the air out of the plumbing. The pump needs to sit below the water level, below the tank would be better. Think of it being set up so that the water is siphoning into the intake, not the pump pulling the water up over the edge of the aquarium. With the pump off, water should stay in the intake tubing/piping. 

Thanks for the info. It's this bad boy right here - https://www.bulkreefsupply.com/varios-2-controllable-dc-pump-792-gph-reef-octopus.html

 

There's surprisingly little detailed info about it available online really, but "Submersible or External - Perfect as a return, closed loop, or reactor/filter pump." is part of the spec sheet.

 

Assuming the whole system is a closed loop and the pump housing is designed to hold the pressure it generates (which I assumed was a given), wouldn't it be basically the same additional load on the pump whether the additional tubing distance onto the intake or the outtake? I see that you're saying the answer is "no", but that's how I was thinking about it and if I'm wrong I'd be interested in understanding why.

 

The pumping action itself is creating suction and it makes sense that this load would be tacked onto the work the pump is doing. But I don't get why that load is more of a burden for the pump. Like say you got it running mounted to the ceiling above your tank. I would imagine the work of gravity would add onto the output power and this extra boost on the downward trip would offset the suction required to pull the water up - total distance pumped being the only variable that would affect the stress on the pump since the water is starting and ending at the same level. Does the reason this isn't true lie in the design of the pump?

 

Thanks again for the helpful reply 🤙