<a href=showthread.php?s=&postid=7394718#post7394718 target=_blank>Originally posted</a> by bosox
One reason to maximize flow between your sump and display (aside from the aformentioned reasons) would be for additives. If you use a kalk reactor or calcium reactor (or even if you manually add supplements) it is obviously more dilute with a higher flow through the sump. If you have a fuge underneath as well, you will have greater nutrient exportation, and more 'pods' being pulled up to your display for fish food. Furthermore, if you use biological filtration (LR, DSB, etc) it would stand to reason that greater flow past these 'filters' would aid in the processing of ammonia and nitrates.
Do what works for you, but I'm a strong believer in strong circulation. It has worked wonders for me. Just my two cents
matt
This is the typical...dare I say..."American" approach to designing a system. Larger pumps = better. But after adding up the wattage of running your sump return as your main circulation pump (what, a 2000gph pump or larger?...thats gotta be at least 200 watts), as well as everything else...like a pump for a beckett at another 150-200 watts...lol...thats alot of wasted energy and heat.
Here...read this thread I started as Herbert T. Kornfeld...
http://www.reefcentral.com/forums/showthread.php?threadid=550482
There are many more advantages to running your sump as a low-flow sump...lower electric and heat are just two of them. Calfo has always been an advocate as well of these methods.
As for the quote above...those reasons arent really true. Additives spread fast enough with just 200gph (more overseas reefers use this approach and have no problem). Think about it, if a heater can keep a whole 180g tank warm with just 200gph of flow through the sump in a 60degree room, your additives will have no problem. As far as nutrient uptake, same thing. Look at phosban reactors...you can run them with as little as 50gph, and at most 150g...so that 1000gph you run through your sump is kinda useless. Calcium is the same. It distrubutes fast enough...even with just 100gph of overflow on a 300g (DNA's TOTM). As for DSBs and plenums, you actually want to run low flow across these areas to prevent oxygenation of the upper layers.
The only area where higher flow MIGHT be an advantage is with a refugium, but its not so much the throughput as it is the current. Do you really think macros are going to remove everything in one pass? Or a skimmer for that matter? You can just as easily run a powerhead in the refugium to give the macro algae the current it likes (pods actually prefer lower current), OR, make the refugium long and narrow to maximize the flow that you have. Some people prefer lower flow through the refugium too. This is a small area considering the minor contribution that the refugium will make anyways.
The benefits of a low flow sump are many...
lower electric bills
lower heat
less noise (no toilet in the overflow) to muzzle
less evaporation
better skimming
Yep, better skimming. Calfo suggests the longest overflow you can fit, with a low flow...just enough to skim the top layers of the tank water's surface where the proteins naturally build up. Then feeding this directly into the skimmer, of a countercurrent or recirculating needlewheel variety. I have done the change myself and found many advantages...including nastier, darker skimmate than before. See, with a high flow pump, you are actually mixing more of the proteins that the skimmer cant catch fast enough back into the tank (they pass the skimmer and get blended back in). With a low flow... the skimmer gets a longer period to get those proteins (and other things of course).
The point...put the smallest pump you can get away with on the sump return...the loss due to head-pressure will be what...the equivalent of 10 watts maybe when if you used a larger pump, like a 100gph one that uses 100watts...you would lose 30 or more...not to mention the extra wattage you are using up front (100 rather than 28).
