What size pump?

[legends92]

I'm getting ready to the purchase the Amiracle Slim Line 250 Wet/dry filter for my 75 gallon tank. Can anyone assist with what kind of a pump I should purchase and how powerful should it be? The Slim Line 250 is made for a 100-180 gallon tank. This is what they recommend on their website:

The Most important part of your filtration system is the pump. No other part of your system is required to work 24 hours a day without fail.

A good rule of thumb to follow when purchasing a pump is to obtain one that has a little more capacity than is required, for it is far easier to reduce the flow from a pump than it is to increase it.

The pump that you choose for your system should be able to move enough water to turn the volume of your system over approximately 3 to 5 times an hour at the point where the water is being pumped into your tank. Remember that each 90 degree elbow placed between the pump and its discharge into the tank will add one foot of additional head pressure. The head pressure decreases the output of the pump. Please remember that some larger filters require two overflows.

It still doesn't tell me much. Can anyone please help me? Thanks.

 

[captivereefs]

How big is the drain going to the overflow box? If it is 1" you can really only run a pump that is about 700GPH max. Any bigger and you will drain the sump faster than it can flow down the overflow. A mag 7 is a perfect pump for the job!

 

[legends92]

I'm not sure, but here is a diagram of the setup. Can this help determining what kind of a pump to get? http://www.tplastech.com/amiracle/slimlineinstructions.htm

 

[fishfreek]

My best guess would be that its a 1" drain line and it only shows 1 U tube so I would stick with the max flow rate of 700GPH thru the overflow. With that known you want to get a pump that pumps no more than 700GPH at the head height you have your tank at. Head height is calculated by measureing the distance from the bottom of the sump (where the pump will be) to the top of your tank (max height the pump will have to push the water up to get back to the tank).

Different pumps will perform differently at specific head height so a pump rated for 900GPH at 0' head might run at 600GPH at 4' head as an example. Pump manufacture's will have head height charts showing flow at given head height.

 

[legends92]

Thank you all for your help. With this inofrmation, I shouldn't purchase the Mag Drive 7 because the flow rate is 700 gph @ 0' headand 480 gph @ 4' head. Should I just purchase the Mag Drive 9.5 which is 950 gph @ 0' head and 800 gph @ 4' head? Here the link to the chat http://www.reefgeek.com/manufacturers/danner_flow_rate.html

 

[captivereefs]

The mag 9 may be ooverkill and will need a ball valve to back it off. The mag 7 while under the max GPH rating of the overflow would do a good job. Is your return pump your main water movement method or are you going to run some powerheads?

 

[legends92]

Not sure. If I decide to only use the return pump for water movement, will the MAG 7 be sufficient?

 

[captivereefs]

Not really, it will lack the power to do uch in the way of movement in a 75. You could always run a SCWD on a mag 9 and be safe. Plus you would get the wavemaking effect the SCWD offers. To see what a SCWD does vist www.3iqventures.com

 

[legends92]

That seems like a pretty nice product.

 

[mikebranson]

Not really, it will lack the power to do uch in the way of movement in a 75. You could always run a SCWD on a mag 9 and be safe. Plus you would get the wavemaking effect the SCWD offers. To see what a SCWD does vist www.3iqventures.com

im a noob and looking into sumps as well - how would this SCWD make a mag 9 safer? wouldnt the water flow rate be the same and "outrun" your sump drain at 1"?

TIA