Flow Thru Refug?

[petrasb]

I was told that you don't want to be circulating the total gph thru you refuge as you are your whole system. Is this true? I am doing about 2000 ghp in a 300gal system, the water goes down into my sump, then into my refuge, which is a 75 gal tank and I have 2 return pumps at the end of it going up to my display.
It was suggested that I place one of the pumps in my sump to slow down the water going thru my refuge.

 

[jetchris]

yes slow water movement in fuge

 

[horsesziggy]

my 450 has a dart hammer roughly 4500 glh at the sump and i trickled off a 1" line to my second sump with 400lbs live rock, then put a 900 glh 0n my refuge, now i'm hooking in to more refugiums to grow calurpa so slow flow is the way to get max results at least in my set up. sal

 

[xyzpdq0121]

You want about 3x-5x water flow through your fuge AND sump..... Much more then that IMHO is doing you more harm then good. Use a closed loop or pumps in your tank to do water flow and for your tank I would keep your water rate to around 900-1000 for your fuge AND sump.

 

[cameron]

petrasb;44474 wrote: I was told that you don't want to be circulating the total gph thru you refuge as you are your whole system. Is this true? I am doing about 2000 ghp in a 300gal system, the water goes down into my sump, then into my refuge, which is a 75 gal tank and I have 2 return pumps at the end of it going up to my display.
It was suggested that I place one of the pumps in my sump to slow down the water going thru my refuge.

This has been a huge topic of reading for me lately. The quick answer is depends on what you are keeping in your fuge. For most common good algae types (ex: Chaetomorpha and Graciliaria) about a 20x flow through the fuge is a good rate. You want to keep the water moving as to crush cyano and such as well as provide plenty of gas exchange for the algae. If you want to create a pod farm, you can slow it down but tests I have seen indicate nothing below 10x is good. These 10x/20x numbers are dependant on the lighting as well. The more lights you hit your fuge with, the more flow you want since growth will be higher. Since this algae can't leave your tank to get more "air", you need to supply it with as much air as it needs and then some. This comes in the form of flow. Works virtually the same with stoney coral.

Flow in the sump gets trickier. Slower flow means less noise, less energy and heat from a larger return pump and more "contact" time with the water. The first two statements are very good reasons to slow things down. The later is somewhat suspect depending on skimmer size. If your skimmer is too small for your system, slowing down the flow could be important. If your skimmer is oversized (yeah... yeah... no such thing, but I mean you are skimming at a very effecient level), speeding up flow is a good thing since waste gets to your skimmer faster. Think of it like a train carrying goods. If the skimmer is a station and can only handle 10 units but the train is carrying 20, you want time to clear out those 20. If your skimmer can handle 40, you want the train to run faster so you can fill the 40 up faster. This assumes you buy into this contact thing to begin with. A lot of experts I have been reading simply believe the more water circulation you have (to a point) the faster the "poop" gets to your skimmer and taken out. Even if it takes three passes it will get it out before any harm can be done.

 

[petrasb]

I like your thoughts. I am lucky to have a basement, I am draining down into my sump, then into my fuge, which is full of cheato. I have a MRC-4R hooked up to sump, which is good up to 1100 gal. My display is 175, sump is about 30 gal and fuge is 75 gal. I just purchases a 1" sea swirl and added another pump at the end of my fuge, so now I am circulating about 2000 gph. I was circulating only 1300 gph, which I think was too slow, but things where working well, my fuge is full of pods. I also kept 4 small power heads in display for flow.


So, should I go back to the 1300 gph for my total circulation and making a closed loop to run my sea swirl in my display, or keep the whole system circulate fast by keeping the 2000gph?

I would make a closed loop between my sump and display, but the MRC makes way too many micro bubbles, I tried it, and I have to let them work their way out going thru the refug.

Maybe I should just give it a few weeks to see what happens with the extra flow thru everything.

 

[cameron]

Keep in mind the 10x-20x is a general rule of thumb for the size of your fuge not sump or system. If you system is 300 gal total and your sump is 75 gal with a 40 gal fuge in it about 400-800gph would be a good number for your fuge. Your sump doesn't really care to be honest. As long as you are getting at least 3x your total water volume passing through the sump, your skimmer will have plenty of time to do its job. You can run more water through it if you want but IMO it doesnt matter if you 3x or 20x through your sump once you throw out the larger pump (heat, energy, etc) and noise issues out. There will be some differences in skimming, but I believe them to be relatively minor (my opinion anyway). The main reason people slow down the sump flow is generally speaking it is a waste of money to run 10x flow through your sump since larger pumps cost more to buy, cost more in energy, generally are louder and can put out large amounts of heat that must be cooled one way or another.

I personally would leave flow through my fuge at 1300gph which right in between 750-1500gph or 10x-20x. I would add the closed loop or stick with the pumps. If you are growing SPS under some big lights you are going to want more than 2000gph in the main system.

 

[petrasb]

Thanks for you input. My refug is 75 gal and sump is 40 gal, so I will use the 1300 gph pump to rum thru my sump and refug and will put another 1300 gph in a closed loop in display tank, which I already have 4 small power heads in. I do have a lot of sps, clams, & softies.

 

[cameron]

Sump/Fuge flow seem good to me at 1300gph. I would shoot for at least 3500gph in the main system and probably closer to 5000gph depending on how your powerheads are arranged. I am finding that 2400gph-ish range on my 120 with the proper powerhead arrangement is blowing the sand off the bottom.