225 Gallon FOWLR system build... ?'s w/ sump

[jrcastro]

Starting to plan for a FOWLR system and have a few questions.

Build Details:
225 Gallon Display Tank (8x2x2)
75 Gallon Refugium/Skimmer Sump
Mid/High density stocking planned
Skimmer is a Reef Octopus 2000 or 3000 rated for 400 gallons
Pair of Koralia 4’s
QuietOne 4000 Return pump
100-150 lbs of Live Rock
100-150 lbs of Sand

Questions are:

1. Is a there any benefits to adding a Refugium in the sump?
(It would consist of rubble LR, DSB & Chaeto in a 40 gallon sectioned area)

2. I have about 15 gallons of BioBalls any benefits in using?

Thanks in advance

[anbosu]

How many gph is the Quiet One pump? If it isn't crazy high you may want to add more flow to your display, depending on the fish you are keeping.

I think there is a benefit to adding a refugium if you can, it gives you a place to grow chaeto so you can export nitrates, etc. Plus you get a few more pods in your system that way.

I wouldn't bother with the bioballs, although they will help you break down the ammonia to nitrates -- just not any further.

[namxas]

I agree...no bioballs, more rubble. Personally, I've never been a fan of DSB's, but some do folks like them.

A QO 4000 isn't going to be enuff pump for that tank, IMHO. Also, I prefer CL's to PH's...since you have a nice new setup in the works, why stick ugly PH's in the tank if you don't have to?

[Stuart60611]

I think to answer your question you need to more fully develop your filtration approach. If you plan on keeping a bacterial driven system with either the dosing of vodka, vinegar, etc. or the use of carbon based pellets, then I do not think you will want to keep a lit refugium as it will likely be counterproductive. I also do not believe in sandbeds in either the display (unless your fish need one) or the refugium. I think in the end they seem to always wind up being nutrient sinks and therefore prefer not to have one in the refugium, and if you must, only a very shallow one in the display. I have a bacterial driven system, and the way I use my unlit refugium is primarily as an area to add biofiltration in the form of a lot of rock and avoid crowding my display leaving more swimming space for my fish. Definitely do not use any bioballs because they will, as counter-intuitive as it may sound, negatively affect your system's filtration (are a negative when used with rock). Finally, a SRO 2000 is not going to cut it on that system, but a 3000 should do the job.

On the negative impact to system filtration from the use of rock and bioballs, I refer you to the below:

5. Remove existing filters designed to facilitate the nitrogen cycle. Such filters do a fine job of processing ammonia to nitrite to nitrate, but do nothing with the nitrate. It is often non-intuitive to many aquarists, but removing such a filter altogether may actually help reduce nitrate. So slowly removing them and allowing more of the nitrogen processing to take place on and in the live rock and sand can be beneficial.

It is not that any less nitrate is produced when such a filter is removed, it is a question of what happens to the nitrate after it is produced.

When it is produced on the surface of media such as bioballs, it mixes into the entire water column, and then has to find its way, by diffusion, to the places where it may be reduced (inside of live rock and sand, for instance).

If it is produced on the surface of live rock or sand, then the local concentration of nitrate is higher there than in the first case above, and it is more likely to diffuse into the rock and sand to be reduced to N2.

http://www.advancedaquarist.com/issu...t2003/chem.htm (http://www.advancedaquarist.com/issues/august2003/chem.htm)