water cycles

I am putting up a new tank 125 72 inches long.

I was wondering please more then one person answer this question because I know that there is more then one aswer. How many times should the water cycle from the main tank the the sump/refugium in an hour?

Roger

 

Don't know anything about salt water.

Overflow:
Q=4.58*H*L^(3/2)
where
Q is the overflow in Cubic Feet per Second (CFS)
H is the dimension from the top of the overflow (the weir) to the water surface in Feet
L is the length of the overflow in Feet.
1 CFS = 448.83 gpm

This is general weir equation with the coefficient (2.67) being conservative.

Example

Overlow height (H) = 0.5 Inches
Weir Length (L) = 2 Feet

Q= 4.58 * 2 * (0.5/12)^1.5
Q=0.077907382 CFS
Q= 35 gpm

At H= 1.0 Inches
Q= 99 gpm

TR

 

What Jones is saying is that the overflow is dictated by the pump size. An overflow can only remove what is put back into the tank, no more than that. So if you have a pump that can handle 400gph but an overflow that could handle 600gph your overflow CANNOT suck more water out than the pump can put back in. It's simple, the weir sit 1/8th-1/4" above the water line, if more water overflowed the water line would then be below the weir and could not overflow. Generally a 1" connection in the back of the overflow box is rated for 600gph. 2 Utubes or 2x 1" bulkheads= 1,200GPH. The cycle time of a sump should be between 5-10 times per hour. At that you'd be looking for 625gph-1,250. I'd get an Eheim 1262 that should be around 900GPH at the actual return point. You could go a little larger than that but may need to restrict the output of the pump with a ball valve. What you are interested in with the sump is "contact time". If the water moves to quickly through the sump/fuge the equipment will not strip the water clean.

 

great info thank...

Well I want the water through the refugium to move throw slow. I could use a sump with the filter pad in it, and use a seperate pump to feed the refugium? how would that be done?

Roger

 

thanks. any inline recomendations for pump. That would help keep the temp down.

Roger

 

Eheim pumps run the coolest since they use the least amount of electricity. Instead of adding another pump think about teeing from the return or suction line to the fuge. Add a ball valve to slow the water headed towards the fuge to what you'd like it to be. I added a tee and a valve headed towards my fuge from my return line. It was very easy to do.

 

that sounds great so my sump and refug are differnt? also is there another over flow on the refug to the sump? How do I get the water back the tank this way?

 

http://cgi.ebay.com/Eheim-1262Hobby...QitemZ250034464042QQihZ015QQcategoryZ46312QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

is this the pump you were talking about?

 

Well I must not be as good at math as I thought. Can someone please tell me how much water this over flow will handle?

Also how close should I push the limit with an over flow. I mean if it handles 1,200 gallons should I do 1,200 gallon pump or should I do 950 gallons to be safe?

Double Bulkhead overflow filter box.
The dimensions

8.5"L x 10.5"W x 12"H
1inch tubes

Thank You so much for your help.

Roger

 

Your overflow sounds to be a 1,200gph. It's not the size of the overflow, it's the size of the tank and sump that make all the difference. You can use teh same line that brings the suction water into the sump to feed the fuge. You want the fuge barely trickling anyways. Just tee the line and add a ball valve to adjust the output.

 

ok I under stand that.

my question is the here take a look as these very quick scetches are any of these what you mean?

 

oviously pictures not drawn to scale.

 

what abou this one?

is there a better way?

Roger

 

I forgot to draw the inlet and the pump but oviously it would come up from the sump to the main display tank.

 

You've got some good ideas and I wish I had not just got called back to work. I have a sketch somewhere on the computer I will upload later or redraw.

If you take a look at the first drawing you will understand that you will be running full force through the fuge, That could be to much. What would work better is to switch your skimmer space for your fuge. Make your fuge first and put the ball valve on the side discharging down towards the fuge. This way it will back the water up and force it towards the skimmer. You can then fine tune the fuge to run as slow as you'd like and it will then overflow into the skimmer sump.

 

great looking forward to the sketch.

I was wondering I read that you want the protein skimmer first because it removes all the good stuff in the water too if it is after the refugium then it will remove the belificial stuff also. this is a Question I only read it I have not tested it my self.

Roger

 

(I am just posting here so that I can come back to this information later. Loads of good info, don't want to have to ask the same questions.)