Return Pump

D

Drill Sergeant

Member
Hello everyone

I'm looking to get a good return pump for a 90 gallon (reef ready) AGA. The predrilled return hole in the overflow box will only allow me to put a 3/4" bulkhead on it, so I'm really looking for a pump that has a 3/4" output.
What do you think about the Blueline 1100 pump?

Or do you have any other suggestions?

DS
 
J

jupiter

Guest
Originally posted by Drill Sergeant
Hello everyone

I'm looking to get a good return pump for a 90 gallon (reef ready) AGA. The predrilled return hole in the overflow box will only allow me to put a 3/4" bulkhead on it, so I'm really looking for a pump that has a 3/4" output.
What do you think about the Blueline 1100 pump?

Or do you have any other suggestions?

DS
Click to expand...

FYI, as long as you can accomodate the diameter of the pump's input, it doesn't matter how small the output diameter is. You can't restrict the water pulled in by the pump, but you can restrict the water leaving the pump as much as you need. So, for example, if your pump has a 1" in and a 1" out, your sump MUST have at least a 1" diameter for water to enter the pump. But you could reduce the diameter of the water leaving the pump to 1/2" if you wanted.

Think of it in this way: if you have a powerhead in your tank and you think it is too powerful, you can adjust the knoby-thingy to reduce the flow rate. The return pump is the same thing except on a larger scale.

I hope that made sense. Anyway, buy the best pump you can and don't worry if it's too large (within reason of course ;) ). You can always reduce the flow.
 
J

jupiter

Guest
I took a look at the Blueline and I'm going to say don't use it. Assuming you have a height of 4-5' from the pump to the tank, this will give you a flow rate of ~ 900 gph. This works out to a turnover of 10x the volume of the tank. 10x is usually the minimum recommended flow rate for a reef tank. Also, the 900 gph mark does not account for bends in the plumbing, friction, and any other forces or turbulence. You might end up with only 600 gph in the end. Find a pump that can handle about 1300 at 4' head as a minimum. When you install the plumbing, include a (expensive) gate valve to control the water flow since your overflow box might not be capable of handling the flow.

This may seem like a lot of redundance but in truth, redundancy is key. From my own experience I have gone through a lot of return pumps because they are good at the time but end up being much too small later on. And it is always good to buy something with the expectation of upgrading, especially something like a return pump. Return pumps can always be scaled back if they are too strong at the present but opened wide up for the newer, larger tank. Return pumps are also something you will always need for your tank.
 
Caterham

Caterham

New Member
Hiyas,

I just thought that I would chime in here and give a few of my own thoughts :)

You should NEVER restrict the discharge on a centrifugal process pump with a valve at the pump, NEVER. When the discharge is restricted near the pump, the pump immediately begins to operate off of the best efficiency point (BEP). This creates a radial force on the impeller and attempts to bend the shaft. This is just the laws of physics and it cannot be avoided. Any pump running against a discharge valve that is throttled back will have a decreased life expectancy, however long or short.

Instead, you should probably run a discharge bypass in the event that your pump is making too much flow. Install a T fitting on the discharge line as it makes its way up towards the display. You want the T to be just past the top of the sump. Install a valve just past the T fitting so you can decrease the flow to the display as needed. Run a line off of the T fitting back to the top of the sump. This will allow you to control the flow that goes to the display and let the pump operate at or near its BEP as well. You can also divert all of the flow back to the sump when you need to perform maintenance or have any other tasks that require a calm tank.

How much flow you need really depends on what you would like to keep! Good luck!
 
Scooterman

Scooterman

Active Member
I'd prefer redirecting the flow as mention, over restricting it, which also in addition makes the pump run harder and HOTTER! Thus you get the shortened lifespan. I say this but I have no proof, just experience from my employment in the Oilfield working with pumps from time to time. This being said, just in case someone throws a bashing my way LOL! :explode:
 
J

jupiter

Guest
Good info. It took me a minute or so to understand it ;) I like it!
 
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