Power heads or closed loop???

[skippy12094]

Hey all,
I am having some difficulty in deciding how to design my new system. I recently bought a new 90 gallon with one corner over flow. The corner overflow is a 1" bulk head. I think if I remember right 1" can only handle about 600-700 GPH but Im really not sure (more would be better). If this is the case then the flow though the aquarium is only about 6-7 times an hour. I have read that some people like their aquarium to turn over 25-30 times an hour. Going by these numbers I would need somewhere in the neighborhood of 2250-2700 GPH. My question is how to accomplish this if my over flow will only handle 600-700 GPH; this leaves me behind about 2100 on the high side. What are my options? I could use a closed loop but I really don't want to drill a hole in the new tank, I could put in a bunch of power heads but if I go that route I should get a wave maker but that gets costly and I don't have a lot of money to work with right now. What I was going to do was purchase the blueline 70HD. I was thinking I could use this pump as my return and then TEE off of that and run 1" PVC up to the top of the tank then reduce it to 1/2", run that down into the tank and I was going to TEE off of that to the back corners, use line loc and have to jets. Then run another piece of PVC from the same TEE to the front of the tank, use one more TEE and go to the front corners and again use line loc and have two more jets and that would keep water moving really good. I would also use valves to slow the flow from the corner jets down if I had to to keep thing from blowing all over. Does anyone have any ideas on how to accomplish the flow I want in an easy not too expensive way and still make my corals and fish happy again? Thanks

 

[Smitty]

Two moderately priced power heads (IE: 50.00 each) with each one placed on each side of the tank would be your best bet IMO. What are you planning on putting into the tank? It is good to have around 10-15x's tank volume for flow but some special coral will need more.

If I understand your thoughts on the pump I don't think it would work. Are you saying that you would have that one pump return to multiple locations in the same tank? The problem is that your return will be limited to what the tank will drain into your sump. So, if your drain only goes 600-700 gph then that is the max you can put back into your tank or the sump will go dry (you will need to address head height loss so you would still need a pump that does more than your max drain).

 

[skippy12094]

Thanks for the reply. I think I am going to do what you suggest. I will buy a smaller blueline and then use two power heads to make the flow I need. I want 2700 gph for this tank. I will be keeping a bunch of sps and LPS. I want it to look nice but I also want the tank to be able to grow the corals. My 36 bow has never been able to handle growing corals and I cant seem to figure out why. I think it has something to do with the flow. Oh by the way how many gph do you think a 1" overflow can handle?

 

[Smitty]

I have no idea how much flow goes through a 1" pipe... I haven't tested something like that yet.

 

[Tomchong22]

A 1" overflow will produce somewhere around 600gph. That is a pretty big overflow lol. If you don't have a strong enough pump you will end up flooding your sump

 

[amdninjaboy]

I dont think that will happen Tomchong22. The water that overflows has to be pumped into the tank so it can overflow.. Too strong of a return pump can pump the sump dry or overflow the main tank but dont think you would overflow the sump.. I drilled my 90 gal and designed my own overflow tubes.. Im running a mag9.5 return pump and I have it throttled back about 30%.. I figure im doing about 400gph through my sump..

 

[Tomchong22]

I dont think that will happen Tomchong22. The water that overflows has to be pumped into the tank so it can overflow.. Too strong of a return pump can pump the sump dry or overflow the main tank but dont think you would overflow the sump.. I drilled my 90 gal and designed my own overflow tubes.. Im running a mag9.5 return pump and I have it throttled back about 30%.. I figure im doing about 400gph through my sump..

You can overflow the sump if your overflow box is set low enough in the water and your return can not keep up.(had it happen when setting up my tank) He just has to make sure that when placing the depth of the overflow to make sure it is not to low and not to strong for the return pump. But you are correct after the initial set up you can't really flood the sump unless the power goes out and there is no hole on the return line to break the siphon.

 

[skippy12094]

The overflow pipe returning to the sump is 1". There, as far as I can see, is no way to adjust the height of the drain pipe. It looks like the tank will fill to a certain height then start draining. I was thinking of buying a blueline 30 hdX for the return pump but if I have a refugium do I want to slow the flow down though the sump. If I return 600gph to the tank then the drain will drain at 600 gph though the sump. Is that too much? should I look at a different external pump maybe smaller? Also, the fittings on the pump I was going to buy are 1". I will have to mount the pump perpendicular to my sump because there is not enough room in the stand for the sump and pump to be in line. I was going to drill a 1" bulkhead and run a short piece of pvc to a 90 elbow (union and valve in there also) and into the pump. Will this be ok or will it cause cavitation. I read somewhere that if you do that you should increase the bulkhead size by 2 (so 2" bulkhead and pvc) then reduce it to 1" at the very end at the intake of the pump this way you reduce the cavitation. Does anyone have any ides on this? Has anyone mounted a pump differently and been fine?

 

[Smitty]

IMO that isn't too much flow for the sump depending on how you have it all set up. If you have your tank draining into section one, then going into section two with rock/macro/whatever, and then into section 3 to return you should be fine.

I can't help with the pump setup location... I have no idea.

 

[skippy12094]

Thanks though.