6x2x2

[fatfishman]

Hello again people,

As you have probably read from another topic i posted on here i am getting a 6x2x2ft marine aquarium with sump and a few other bits and was wondering about a few things. Mostly about equipment. I beleve that 6x2x2 means that my tank has a volume of 650 liters, please correct me if im wrong.

I already have one 300W tetratec heater from a tropical tank and was wondering if two of these would be sufficient to heat a tank of this size?

Secondly i need to buy a return pump for the sump and was just wondering how you work out how much flow rate you need.

Another thing i was wondering was about powerheads in the tank and what sort of flow rate would i need from them and would two be enough for my tank. Also what make do you recommend and what model do you use?

Sorry im always asking but i think its best to hear from experience, if i am wrong about anything please dont hesitate to correct me

Thankyou

 

[andywg]

2 300W should be fine.

I go for around 5x turnover from the sump to keep things ticking over nicely.

The turnover in the tank depends on what you want. The general rule stated is:

FOWLR: 10-20x
LPS: 30x
SPS: 40x+

I always recommend Tunze for powerheads. They simply are the best. In a tank that size I would also consider a Tunze Wavebox. It's expensive but it moves all the water in the tank like waves rolling into a reef. A tank that size would be looking at a single wavebox and 2 or 3 tunze nano streams (6045).

 

[fatfishman]

Ok thankyou andywg,

I will go for around a 3000ltr return pump then

To start with i will just have FOWLR but would like to move onto corals and such gradually so i will probably add to my turnover accordingly

cheers

Edit - I have just seen a 3500 lph Aquamedic Ocean Runner Pump for £66.95 looks good, do you have any experience with Aquamedic?

 

[SkiFletch]

24 cubic feet (6x2x2) is equivalent to 679.6043184 liter (thank you onlineconversion.com). So yeah you want around 3000L/hr through it, but that is NOT the pump you select. You select a pump based on the flowrate at a specific head pressure... Pumps have a "pump curve" which shows that as head pressure increases, flowrate decreases. Assuming your sump will be located in the stand, you're prolly talking about 5 feet of head pressure on the pump. And a 3000lph pump at 5 feet of head will probably only put out around 2000lph. You need to be looking in the 4000+lph range for the pump and design your drains for 3000lph

 

[fatfishman]

24 cubic feet (6x2x2) is equivalent to 679.6043184 liter (thank you onlineconversion.com). So yeah you want around 3000L/hr through it, but that is NOT the pump you select. You select a pump based on the flowrate at a specific head pressure... Pumps have a "pump curve" which shows that as head pressure increases, flowrate decreases. Assuming your sump will be located in the stand, you're prolly talking about 5 feet of head pressure on the pump. And a 3000lph pump at 5 feet of head will probably only put out around 2000lph. You need to be looking in the 4000+lph range for the pump and design your drains for 3000lph

Ok cheers

How do you design a tank for a specific flow rate out of interest?

 

[Musho3210]

2 300W should be fine.

I go for around 5x turnover from the sump to keep things ticking over nicely.

The turnover in the tank depends on what you want. The general rule stated is:

FOWLR: 10-20x
LPS: 30x
SPS: 40x+

I always recommend Tunze for powerheads. They simply are the best. In a tank that size I would also consider a Tunze Wavebox. It's expensive but it moves all the water in the tank like waves rolling into a reef. A tank that size would be looking at a single wavebox and 2 or 3 tunze nano streams (6045).

im probably going to get beaten down repeatedly with crazy remarks, but what the heck. 30x turnover is too much for LPS IMO and IME, my torch, brain, candycane, and bubble are in a tank with 30x turnover, and they are by no means good looking. Squished by flow, closed because theres too much around them etc. I have to find a spot with very very little flow before they actually look normal. So i would give them 10-20x turnover, leathers and some softies 30x, and sps 40+x.

 

[fatfishman]

Ok thanks Musho3210

 

[SkiFletch]

Heh, well first you choose your desired actual flowrate, in your case 3000L/hr. Then you determine your head pressure, in your case likely around 5 feet (~1.5meters). Then, you choose a pump. In the UK, I'd prolly look into Aquamedic Oceanrunner pumps as they seem reliable. I know Matt uses one as his return pump. So you then lookup the pump curve found here, page 3. There you'll see the pump curves for the different model oceanrunner pumps. The OR3500 seems to fit your profile exactly. If you look, at 1.5m, the OR3500 produces 3000lph worth of flow, pretty much exactly what you want.

Next, you design your drain. 3000lph (~800gph) worth of flow will require a minimum overflow drain size of 30mm (1.17"). That means your bulkhead must be a minimum of 30mm. I believe the nearest bulkhead size would be 32mm available in the UK. I would reccomend having 2 of them, in case one fails, the other can take up the slack.

Also at 3000lph, you will need a total of 300cm worth of open top length on your weir to keep noise down. You need to now choose which type of overflow you want to use. Durso Standpipe, Stockmann Standpipe, or Calfo Overflow. I've recently discussed the merits of all 3 so a simple search should net you the info you're looking for. Whichever type you choose, just make sure you have enough length on the top of your weir.

Finally, you choose your return fittings. You can either drill bulkhead fittings, or take the pipe over the side. Either way I reccomend having the pipes just near the surface both to help aid surface agitation, and to provide a second level of back-siphon protection.

Lastly, design your sump tank itself. melevsreef.com can help in this endeavor as it has lots of good sump ideas.

Hope that helps, I'm sure you'll have questions

 

[fatfishman]

Thanks Skifletch