baffle placement for refugium

K

kpatrick

Guest
I am wanting a 30 gallon refugium filled with cheato. What is the minimum number of baffles needed and still function properly? Do I really need one where the water comes down from the tank? Is one sufficient by the return pump or do you need 2 or 3 to insure micro bubbles arent an issue?? I dont plan on using sand since its for nutrient export and not pod growth unless someone with experience thinks that the sand is needed.
Thanks
 
coryherb

coryherb

Member
I am still a newbie but... You only need the baffles where you don't want bubbles (ie before the return pump). It is hard for people to answer your question without more detail of how your setting up your fuge. Everything I read has 3 baffles the further apart the better (I have seen that commonly they are 1/2" to 1" apart) in an over under over pattern. Squidd writes that the 3rd is unnecessary and that two would do the job just going over and under. Hope that helps.
 
K

kpatrick

Guest
I was hoping Squidd would jump in. I have seen the diagrams and pictures but I need the specifics that you mentioned like having baffles 1 " apart. The refugium is going to be under the tank and it will be used for cheato (not Pod growth) so do I need baffles where the line from the tank enters the refugium? I am buying a 29 or 30 gallon tank to use as a refugium but my LFS wants an arm and a leg to glue the baffles in for me and each baffle increase the cost. I was hoping to do this myself thats why I was wanting to have the least number of baffles possible (less chance for me to screw up) but still work properly. Also, if anyone could tell me what material I can use for baffles in a glass tank I would appreciate it as well. As stated before there will be no sand in the refugium just macro to help reduce algea in the display tank unless everyone thinks sand is needed. Any help is appreciated since refugiums are new to me.:)
 
coryherb

coryherb

Member
The distance apart the baffles are depends on the flow I believe. If they are too narrow for the flow it will just push the bubbles through. I don't think you will have much flow so don't think you have to worry about that too much. I believe the purpose of keeping down the bubbles in the main tank is two fold. One for appearances and two to prevent air from forming pockets under/in LR creating dead spots. Since your fuge doesn't need to meet either one of those reasons you shouldn't need baffles before it. You don't even have to worry about kicking sand up if no sand.
 
squidd

squidd

Active Member
You guy's pretty much have it here...
That "link" above covers a lot and you may have to read it a time or two to chach it all (or read "between" the lines...)
Basicly as far as "spacing" there is no hard a fast "number" to give...as it depends on flow rate (gph) and "size" (height and width) of the baffles....
Looking below you can see a "narrow" tank would need the baffles further apart and a wider tank could have them closer...
If you ran the 12" tank with 1 1/4" spacing you would only have
15 sq/in "flow space" and the same amount of water would have to go "twice" as fast to get through...(Taking bubbles with)
Let's say in the first example you were flowing 600gph through 30 sq/in flow space...and that was working...
That would be 20 gph per sq/in...
In the next example you would be flowing 600 gph through 15 sq/in...That would be 40 gph per sq/in...Twice as fast...
BUT you could flow 300 gph through that same 12"X1 1/4"= 15 sq/in flow space...
Because that would only be 20 gph per sq/in...
Follow...??
 
K

kpatrick

Guest
Is too much flow a concern with cheato? I know you dont want a lot of flow when trying to increase your pods but since its just going to be cheato what size pump would you recomend for a 30 gallon fuge??
I will also have several powerheads in the display tank for additional flow so just need enough flow out of the fuge to make it 4 feet up the return line and keep the fuge running good so any pump suggestions would help.
 
squidd

squidd

Active Member
Actually, I think it's the other way round...
You want "more" flow for growing pods...partly to flow more nutrient and deitrus laden water "in" to feed them and partly to flow and pull a bunch of them "out" and to the tank where hey can do some good...
And "less" flow for a Macro only Fuge (malnutrient removal) so the macros have "time" to suck up the nutrients...
But not "too slow" that you have poor oxygenaton and cyno problems...
So I "suggest" 7X to 10X "fuge" volume through the fuge (either to the sump in combo with "skimmer flow" or directly back to the tank...)
So for a 30 gallon "fuge" 210 to 300 gph ...which is a relatively small pump...as long as it will "actually" flow that much - 4' head..
 
K

kpatrick

Guest
Thanks Squidd
Do you know how to calculate for 4' head? Should I go with a 400 to 500 gph pump knowing that some flow will be lost going up to the tank or is there a better way to calculate? Also could I put a small PH in the macro area of the fuge to help circulate water to reduce cyno?
Sorry for all the questions just dont want to waste my money on the wrong pump.
 
squidd

squidd

Active Member
A Mag 5 - 4' head through 3/4" line and 2-90* elbows will deliver 276 gph which is right about where you want to be...
Depending on how the tank is set up (height/width/depth) and the flow charicteristics in it with the macros growing...you may want to add a Micro or Mini jet (70-100gph) to keep oxygen levels up...
 
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