Questions about pumps for a 90 Gallon tank

[TONY_C]

Hi. I'm not new to saltwater fish, I have had tanks before but that was back in the 80's and so much has changed that I feel like I am a beginner. I've been reading all I can on reef tanks and pouring over this site and the site blogs for the past two months trying to learn as much as I can. I am getting ready to start setting up my tank and I have some questions.

The DT will be 90 gallons with a sump that is a 30 gallon tank (holding about 20 gallons). I have been reading a lot about algae scrubbers and this is how I want to go. I have already fabricated a Scrubber. I want to use the live rock and live sand along with an algae scrubber to handle all of the filtration requirements.

My plan for the sump is simple, it will be divided into two sections by a glass pane. the first section will be for the DT drain plumbing and will also house a submersible pump like the Eheim 1000 which will be connected to the algae scrubber that will sit over the second section of the sump. This pump will give me up to 250 gph over the scrubber. Of course, the drain from the DT tank will be more than 250 gph so the majority of the water from the sump will spill over the divider into the second section as the drain volume overtakes the scrubber pump.

The second section will contain a lager pump to pump the water back to the DT. This pump will be about 550 gph. My drain from the DT will be 1" PVC and the return will be 3/4" PVC. I also plan to use two power heads like the Tunze Nanostream 6025 (740 gph).

My questions are:
Is the drain plumbing and return plumbing sizes adequate for the flow I am expecting?

Is this enough water flow and turnover in the system?

Thanks in advance and, of course, I welcome any suggestions and criticisms of my plan.

Tony

 

[username in use]

You are kind of at the minimum for flow in the display. I would be shooting for a total display flow of something like 3500-4500 gph.

 

[TONY_C]

You are kind of at the minimum for flow in the display. I would be shooting for a total display flow of something like 3500-4500 gph.

Wow, my first reply is from a fellow Long Islander, cool. So, I was under the impression that i needed 10-20X flow, or 1000-2000 gallons per hour. You are saying I need 35 to 45x flow?

 

[scuzy]

If you're pump is unity pushing 250gph your drain is not going to drain any faster. Get a larger return pump if you want the drain to overflow faster into other section.

 

[TONY_C]

If you're pump is unity pushing 250gph your drain is not going to drain any faster. Get a larger return pump if you want the drain to overflow faster into other section.

Thanks for the reply. Perhaps I wasn't too clear about the sump. If i have the drain from the tank delivering 550 gph to the first section of the sump and the return pump is delivering 550 gph to the DT then the water level in the sump will be the same height in both sections. Then if i turn on the scrubber and pump water at 250 gph from the section of the sump where the tank drain is thru the scrubber and that drains into the second section with the DT return pump, will not the height of the water in both sections still equalize eventually?

 

[username in use]

Wow, my first reply is from a fellow Long Islander, cool. So, I was under the impression that i needed 10-20X flow, or 1000-2000 gallons per hour. You are saying I need 35 to 45x flow?

Yeah, 10-20x is pretty low. Especially considering the flow patterns of the stream pumps like the Tunze, Koralia, Vortechs etc and how wide and soft they push the water. 30-50x is reasonable for mixed reef aquariums and SPS dominant reefs can benefit from flow up to 70-80x the display volume. I ran a non-photosynthetic tank for a while and it was pushing 100x turnover in the display and the sand stayed put and everything was happy.

 

[TONY_C]

Yeah, 10-20x is pretty low. Especially considering the flow patterns of the stream pumps like the Tunze, Koralia, Vortechs etc and how wide and soft they push the water. 30-50x is reasonable for mixed reef aquariums and SPS dominant reefs can benefit from flow up to 70-80x the display volume. I ran a non-photosynthetic tank for a while and it was pushing 100x turnover in the display and the sand stayed put and everything was happy.

So would you recommend:
increasing the water movement by using stronger power heads or making the return and drain piping bigger and increasing the sump pump capacity or both?

 

[username in use]

I would work with power heads. I like 3-5x through the sump, any more just gets wasteful in terms of electricity as pumping it up uses a lot more energy than circulating it with power heads.

 

[TONY_C]

I would work with power heads. I like 3-5x through the sump, any more just gets wasteful in terms of electricity as pumping it up uses a lot more energy than circulating it with power heads.

Thanks. so my sump is good then as far as pumping speed and I will just try looking for bigger power heads. I appreciate your input.

 

[username in use]

Yeah, that's the way to go.

You can stick with Tunze and either get more of the same or go larger and get the controllable ones. If you don't mind the pump on the side of the tank it's hard to go wrong with a pair of Ecotech MP-40QDw's and all the syncing they can do with each other, and the Maxspect Gyre's are seem to be doing pretty well also. You could also do a combination of some of those, maybe a pair of Tunze's and the Gyre.

 

[billdogg]

What style drain are you planning on? If it's the standard "reef ready" Durso style 1" drain, you will max it out at about 300-350gph. 250 - 300 is more realistic unless you like a VERY noisy drain line.

I'm with username - power heads are the way to go to maximize flow in your DT. For my 120DT, I use a eheim 1262 for the return, and it also powers both reactors, so I get maybe 600gph through it, but it has 2 x 1.5" drain lines so can easily handle it. The remaining flow in the DT is through the use of 4 x Koralia 3500gph power heads, and I'm considering adding another one or two on timers to randomize the flow better.

 

[TONY_C]

What style drain are you planning on? If it's the standard "reef ready" Durso style 1" drain, you will max it out at about 300-350gph. 250 - 300 is more realistic unless you like a VERY noisy drain line.

I saw a very clever DIY drain pipe on an English Reef forum, I won't post the link because I'm not sure if it's allowed. It's a full siphon design and it is self starting should the power go out. I am not sure what size pipe will get the flow I need to match the pump output but PVC is cheap. If I go with 1" and it's too small I'll just make it 1-1/4". too big and I can throttle it back with a valve or go to 3/4" diameter.

As for my meager power heads, am I OK to start with those for cycling the tank with live rock and then upgrading as I add corals at a later time? I assume that massive flow is for the benefit of the corals, correct?

And thanks again to you and others who have replied so quickly.

 

[username in use]

As for my meager power heads, am I OK to start with those for cycling the tank with live rock and then upgrading as I add corals at a later time? I assume that massive flow is for the benefit of the corals, correct?
.

Absolutely. That's fine to get the tank cycled with. If the tank is fish only it would be fine to run it the way you are but for corals you really need the increased flow to make sure they are getting thoroughly "washed" with fully oxygenated water. As they grow and get more dense it becomes more difficult to make sure the entire colony is getting enough flow so it is important to make sure there is enough for them to penetrate the coral growth as it grows in.

That is just one aspect of the importance of flow but probably the primary.