Anyone use 2 return pumps?

[sula]

I am planning my sump for my new tank. The tank is a 100g acrylic with a center overflow box. The overflow has two 1-1/2 inch drains. The guy I bought it from only used one of the drains, but I'd like to use both. I am considering having one drain go to the skimmer section of the sump, the other to the fuge section, and then a center return area as I've seen posted here many times. I also am thinking of having 2 pumps for the return, partly because there are two built-in returns, and it seems simpler to connect one pump to each, and also because I already have one pump, a Mag 9.5, which is not going to be enough to pull this off. I'm thinking a Mag 12 for the other return pump.
Does anyone see a problem with this type of set up?
All comments are appreciated :happyfish

 

[modizzle]

I think that set-up should work good for you...I was throwing around the same idea after not dealing with One pump for two return lines...Although I will use dual mag 9.5's for mine which should yield around 1000gph...Just make sure if you are running a feed to your fuge that you are not having a turn over rate more than 5X the size of your fuge...Maybe throw a T connector with a valve to tune your flow to your fuge...Hope this helps...
Kev

 

[sula]

Modizzle -
thanks for the reply. Just wondering, I thought a Mag 9.5 at 5' head would return 750 gph - why do you think 2 would give you 1000? Do you have a lot of elbows and such?
Also, the part about no more than 5X turnover in your fuge - thank you, I had a feeling there should be a "number" for that - is that a general recommendation or does it change according to different variables, kind of like lighting and flow recommendations change according to what types of animals one wants to keep in the tank. I guess what I'm asking is whether there is a "range" of recommended flow rates through a fuge, like a minimum of 2x (anything less and the water wouldn't be moving) and a max of say 10x (anything more would be a tidal wave?)
Thanks for your opinions

 

[modizzle]

You are right with the flow rating for that head loss, although I will be pushing close to 7 feet or so...My dual overflows can support 1200gph combined...I will just put a T connector with a ball valve to control the right amount of flow heading out of my sump...If I have to much flow i will open the valve which will divert water back into the sump instead of the tank(controlling the flow rate)...
Another reason for the dual pumps is because if you were to go with a "T" connector for one large pump you will be using more electricity with a larger pump...For example with the mag 24 you will use 265watts while dual 9.5 will only be 186watts...Just some food for thought...
As far as flow rate for your sump, 5x is a pretty standard turnover rate...If you can, try to shoot for this number...
What kind of sump design are you planning on going with?..Return in the middle chamber or on the end?..
Kev

 

[sula]

I'm thinking the return in the middle chamber. If I'm shooting for 5x turnover in the fuge section I'll definitely have to restrict the flow to that area somehow :thinking:

 

[ddboy]

I think it will be better for 2 return pump in case one of them fail. I also plug 1 of my pump to a UPS just in case of power outage as it happens alot in the summer here in South Cal.

 

[sula]

So do you mind explaining exactly how a UPS works?

 

[ddboy]

It is a back up battery. The APC Smart 1400 UPS I got has 8 outlets for you to plug stuff in. It is designed for computer equipment. But the Smart model can be used to drive mechanical pumps. So I just plug one of my pump into it. If power goes out then the battery will kick in. And it should hold up for a few hrs depending on what size of UPS you got and what you plug into it.

 

[sula]

Cool, thanks :happyfish

 

[acrylic51]

Failure of return pumps are rather minute IMO.....The chances are very slim if you use a good quality pump and you service them like they should be.....IMO a waste of electricity and space to run 2 return pumps on a tank that size

 

[ddboy]

unless you are home all day waiting for the pump to go out or power to go out. It makes sense to use 2 pumps and back up battery. It is nothing compare to what most people spend on their livestock.
I have never had a pump failed on me. but it seems like I am never home when power goes out for hours each time.

 

[acrylic51]

Seems really odd after all these years that pumps just don't go without warning, but it can happen.......What is really the point of having 2 pumps??? None IMHO.....Waste of electricity actually.....You have to match the pumps to the overflow and make sure they can carry the water as well.......Even if the pump did go down if your away and someone is watching your tank it would go noticed.....
I can see the point of having a pump plumbed inline or a backup already in place just in case this sort of thing would happen, but all that would be needed in this scenario would be to just plug the other pump in or flip a switch.......I keep a backup plumbed inline with the system just in case it would happen, but your tank wouldn't die if it went 24 hours without power..... :thinking:

 

[bang guy]

Just my opinion - I have two return pumps.
Eventually a pump will die. In my experience this happens suddenly after a power outage, they just don't start back up again. About 5 years ago I had an 11 year old Iwaki that failed just like that. Luckily, the other pump kept things going until I got home.
Also, I have each pump on a seperate circuit incase a GFCI trips or a short circuit. A few years ago I had a HelloLights VHO ballast fry itself and it tripped the circuit breaker shutting down half the equipment on the tank. Luckily it limped along on 1 set of heaters and the other pump.
I have seen very nice systems crash after only a few hours without the main circulation. A recent example is the Penn State Reef tank. Goegeous tank that had a major crash only 1 hour after the circulation pump was shut down for maintenance.
It also allows me to do maintenance on a pump without shutting off the entire system.
Experience has taught me that redundant systems pay for themselves 10X over the first time they are needed.