External Pumps

[fkshiu]

The Snapper is not a pressure-rated pump meaning that it is not designed to pump water against gravity (i.e. upwards). That's why most people use Reeflo Darts, Snappers and Barracudas for closed-loops where there is the pump is usually placed just behind the tank rather than a good 4 or 5 foot underneath it for a sump return pump. Practically speaking, this means that you are paying for a lot of gph that you'll never get if you use such a pump as a return pump.

You can see in Reeflow's charts that their "flow-biased" pumps like the Snapper loose more flow as head (i.e. height) increases than their "pressure-biased" pumps.

Secondly, for a 185 gallon system you do not need anywhere near the amount of flow on a return pump that any of the Reeflo pumps give you. Most people aim for a 3-5x system turnover rate for their return pumps. Faster flow has three main downsides: 1. more issues with microbubbles; 2. more salt creepa (both due to the greater splashing/flow); and 3. lowered skimmer performance because the water is simply flowing too fast to be taken in and skimmed.

All this being said, external pumps are the way to go IME. Less heat and easier maintance (provided you hook it up with true union ball valves).

Personally, I'm using an Eheim 1260 on my 165 gallon system. A little pricey, but it's efficient, quiet and dependable with the right amount of flow.

[Skimmin]

I designed my sump with a bypass style refugium and I have two drain boxes(one for each 1 1/2" drain). Each drain box will have filter media(metala) in the bottom compartment and a fine filter sock in the top compartment for cutting down on microbubbles. The skimmer is a re-circulating ASM G2 which wiil be piped back into the fuge with the gate valve and drain pipe. I agree that the pump will have a lot of flow but I'm hoping with appropriate valves and unions it will work quietly and efficiently. http://i193.photobucket.com/albums/z.../refugium3.jpg

[jasond]

Good thread! Dont mean to hijack, just a quick question. My new setup is 60G, with about a 20-30g sump. how many GPH would I need to run on my return? Would the Eheim 1250 at 317gph be lots (with a ball valve)? I hadnt considered external but seems people prefer it where possible so I think I will try to go this route.

Thanks for the good info!

[mr_alberta]

Your Ehiem pump might be a little small, but it would work. How far up do you have to pump? Figure that out and take a look at the flow chart for the Eheim and see if you land in the 4x tank volume range.

[michika]

Just an FYI, from the Reeflo website, under the manual for the Snapper/Dart pump, you can valve them back, just not on the intake. By doing so you lower power consumption, it also supposedly extends seal and motor life.

[Skimmin]

The fact that the manufacturer wants you to valve them back is one of the reasons I wanted to go with this pump. For an application in a smaller tank the flow chart for the snapper shows that it can be throttled all the way down to 300gph using a total of 75 watts.

[michika]

I'm going to be using a Snapper as well on my 28g nano. I chose it because of my previous experiences with Reeflo pumps, and because of the wattage draw options.

It sounds like you have a good idea about what you want to do, and I really hope it works out for you.