big pump, little pump ?

[iansfishy]

So in setting up the new tank, im wondering what pumps to get and where to apply them and I would like to hear from some pump and plumbing people. I already have a reeflo dart and plan on purchasing a reeflo barracuda. I planned on using the barracuda for my main return, because I have to go up from the basement about twelve feet and feed my refugium and frag tanks. I was going to use the dart for my closed loop which is going through a oceans motions 4 way, vertically about 4 feet. After doing some math, with water volume and vertical distance etc, would it make more sense to use the dart for the return at about 1500 gph or six times turnover ( through the sump) if i take it up to eight feet, and the barracuda as the closed loop pump at like 4500 gph for like 18-19 x turnover or even valve down the barracuda. I guess its better to have more flow inside the tank then actual turnover right? I never really thought about it until now. OR should I suck it up and buy two barracudas? Its only because a have to go up twelve feet to the main tank, as well as feed a closed loop. If anyone has better suggestions on diffrent pump options it would be helpful. there is about 240 gallons of total water, the main tank is a 180. thanks

[BlueAbyss]

From what I understand about sump style filtration systems (though I'm a newbie, you may want to take what I say with a grain of salt ), you shouldn't have too much flow through the sump. I understand that you need lots of circulation in the tank (which is why people use closed loops and powerheads) but that you only need as much flow through the sump as is needed by the filtration equipment (ie: 500 gph for the skimmer feed, + 90 gph for some reactor, = 590 gph). But this will depend on factors like whether you run a refugium in sump, and how much flow that will need to be efficient, etc.

[mark]

Currently have a Barracuda basement return and Dart (with 4way) on a CL.

Before the Barracuda I had a Iwaki MD70RLT and was looking to replace so contacted Reeflo looking for a ~1000ph with 9' vertical, 9' horizontal and advised the Dart would be borderline. A modified Barrcuda was suggested for ~1500gph at 180w. I ended up going with a unmodified pump and find can get about 2000gph full open but normally run valved back to 1000gph and feed the display only. My fuge is in the basement along with a frag area (part of the sump) and fed by the drains so I'm not pumping to them.

[banditpowdercoat]

What's the GPH of the Dart if you put it in basement and have it push all that head? Your wanting SPS in your tank, right? So using the barracuda as the CL would be fine/. I'm running a Dolphin Amp Master 3000 GPH on my OM-4 in the 150. SO the Barracuda on a 180 shouldnt be bad. Hopefully not need any powerheads, thats for sure. For sump flow, I know slower, the more it acts as a refugeum, and will filter better, and have less microbubbles. I have a Little Giant for my 60g Sump return, About 1000GPH, will most likely have to throttle it back somewhat.

[iansfishy]

I dont think the dart will push the twelve feet needed, and if it did it would be barely. I thought about a bigger pump like the hammerhead to do all the work ( CL and return) but that is at full open and trusting that some check valves on th CL will stop my tank from draining. I guess Ill go with two barracudas, just seems like alot of energy? But I guess if they are both valved down the energy consumption decreases as well. How come you can get more GPH out of a pump if you increase the pipe diameter? Does that still hold true if you say run 2 inch all the way then go down to 1 inch at the end? So after thinking about it for a minute does flow in the tank count as in the "tank" or total wter volume. For example- if the 180 has 120 g of water and i use a dart thats like 19 times turnover in the display thats pretty good. But if its total water volume like 250 g thats only like 13 or 14 times turnover/hour. but with a dart and having to go like six feet and 4 diffrent outlets according to the head loss calc from RC it cuts the GPH almost in half. I guess im looking for someone to justify my buying two barracudas! Thanks.

[BlueAbyss]

Okay, one more thing. With a closed loop, you don't need to worry about head pressure, since the outlets and inlets are at the same level the head pressure is negligible. Even if the pump is 12 feet below the tank, you should get similar flow to a pump that is right below the tank, though there will be some loss because of the length of pipe running to and from the pump.

Count your turnover through the display, not the entire system's capacity. Your corals won't care if you have 30x turnover through the sump, unless they're in the sump.

[Oxymoron]

How come you can get more GPH out of a pump if you increase the pipe diameter? Does that still hold true if you say run 2 inch all the way then go down to 1 inch at the end?

Bringing your 2" line down to a 1" will reduce your entire flow to 1".

You would have to have the pipe and fittings 2" in order to not restrict your flow and essentially choke off your flow.