On your tank, are you going to have a closed loop or other circulation in it? That will also help determine your return pump. On my tank, with all of my flow and circulation coming from the closed loop, I only needed to have a pump return the water to the tank.
Can you explain a closed loop? I only have a small tank at the moment and am in the process of setting up a 72 so I don't know about this yet... So if I have a closed look system I don't need powerheads and a wave timer?? and i guess that leads to, If I have powerheads I don't need a closed loop??
for a 75 closed loop i would run a mag 12 on a SCWD. This is a nice combo for circulation. A closed loop basically cirulates water through the pump. THe pum draws water directly from te tank and returns it to the tank. The pump is a closed system.
Do not run a mag pump external the covers are to fragile and are a dsiaster waiting to happen.
Beckmola, there are many return pumps to choose from. One thing to consider is will this be an internal or external pump. As Cesar has said, heat may be an issue with internal pumps, as is also the case with external (external pumps can get very hot). Mag Drive pumps are great in my opinion. They are also considerably priced. Again they can be used internally or externally, however, i don't advise that you use it externally because it does make noise. It truly is better used internally. Eheim also makes great internal return pumps. They are a bit more expensive that the Mag Drives.
When opting for external pumps, many of those people with larger tanks use Dolphin Ampmasters. However, with a tank your size, I would opt for a nice sized Iwaki pump (American motor or Japanese motor). I do not know the size of tank this is, but an Iwaki 20rlxt or iwaki 30rlt would be great. Remember that it is better to buy a pump that is rated for a higher GPH since you can always lower it. This way, when or if you upgrade tanks, you can still use the same pump.
People utilize closed loops in order to get rid of powerheads (usually the case), or to just add more flow without using powerheads to clutter the tank. So if you have a closed loop, along with a return, it doesn't mean that you cannot have powerheads (or vice versa). Closed loops, like powerheads, are just another way of adding more "flow". However, with closed loops, you will need to drill holes, add bulkheads, and get an external pump to run the closed loop. Some people add powerheads even with closed loops and return.
What size is your tank you will use the return for, and what will/are you keeping in this tank?
The dimensions for my sump are 24.5x12.5x17.5... About a 25 gallon sump on a 72 gallon tank. I am going to run a EuroReef ES5-3. I haven't decided exactly what I'm keeping yet. It's a reef, so, corals, fish, inverts etc.
I would do a sump with the return pump being a mag 12 on a SCWD and than some power heads or another SCWD Mag 12 closed loop. I have a friend that runs the dual SCWD on his 75 and it works really nice. Nice thing about the SCWDS is no ugly powerheads i the tank.
On closed loop... you need a really good/powerful pump, you will also need a SCWD (optional) or some sort of a controller so you will have a good random effect. This can be ball valves or ocean motions. If you are using an acrylic tank, it would be advisable to set some plumbing design on while on its early stage.
With that in mind, here you will need to shell money a little bit more.
You can still use your old powerheads but just hide it behind the rocks or something.
I have closed loop but have to take it down because i cant see the effect i want. Maybe I have small pump (mag 5 on 25g tank).
Well actually, just installed back my three maxijets on a newly acquired "natural wave" electronic wave timer. And I liked it.
Scott just plumbed my new 60 with a sqwd and did a great job. It's very neat and tidy. I'll post some plumbing pics so you can see. He used locline for the returns and it's really cool! I also have Maxi jets on a wave timer.
Aren't you in Lynnwood? If so you can come check it out if you'd like.