Surges, interesting fact

[sfsuphysics]

I always like to increase my knowledge base, refresh my existing base, and when doing so I.. well sometimes I come across interesting bits of information I didn't know before. I experimented with a fairly large (25% of total tank volume) flush style surge device (sorry I refuse to call it a Borneman surge because he reinvented the toilet), and this was a no frills setup, no skimmer, no sump, just soft coral, which did do quite nice BTW except for the natural light which made the temp spike to 90s! Anyways the surge was great, it was high, it was relatively quiet (enough that I didn't care). I always liked the idea or surges, made it feel more reef like (although with the advent of powerful pumps on controllers, e.g. tunze it seems they replicate similar functions).

Now here's the bit I just read, found it so interesting thought I'd post it on, this by our good friend Mr Calfo.

I had no idea surge devices affected skimmers. Do you know why that happens?

It's quite severe... a disturbance and/or irregularity of protein concentratons at the surface of the water collected (or not) by the vascillating level of overflow water (the pitching of water level makes varying "thickness" of protein rich water carry on downstream to skimmer(s). Worse still... the pumps that feed your skimmer (whether they are surface mouth, direct feed or downstream) suffer from slightly fluctuating head (pressure) on the feed pump... and as such diliver fluctuating volumes (albeit slightly) to the skimmer which makes the active foam-water interface fluctuate (bad). In a phrase... fluctuating skimmer pump flow, head or feed volumes will severely handicap skimmate production.

I the original line, thought hmmm full of sh... then read the rest, and the more I thought about it, the more it makes sense... Really is making me rethink the idea of surges on a tank now.

 

[GreshamH]

It shouldn't effect the skimmer if done right.

 

[zepplock]

[quote author=GreshamH link=topic=2462.msg25364#msg25364 date=1191343536]
It shouldn't effect the skimmer if done right.
[/quote]

I agree. In-sump skimmer. No level/pressure/concentration changes.

 

[sfsuphysics]

You sure about that? All of a sudden you dump a few gallons of water into your tank, your overflow hopefully will take up the slack but you'll have a faster concentration of water going into your sump as a result not as much stuff can get "grabbed", hell I can tell this from using my small little pump I keep in my water top off (not automated) when I refill with RO/DI I can hear the increase waterfall of activity from one baffle into the next. If water is going over more rapidly that probably means it went up in height slightly, which changes the pressure slightly (Calfo even admits it might not be much of a change)

 

[LeviT]

Thanks for passing that along. I can see how certain designs could be effected but others may not.

 

[zepplock]

Wait, isn't your overflow always almost 100% used?
Anyway i don't understand how you can have surge and sump at the same time.
Won't it overflow the sump?

 

[LeviT]

Here is a gravity fed mini surge design.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=719623&perpage=25&highlight=custom%20surge%20tank&pagenumber=1

and here is a similar design.
http://www.breedersregistry.org/Reprints/MFM/v11_aug96/simple_surge.htm

and another
http://www.hawkfish.org/snailman/ssurge.htm

They are basically toilets