Sump / Fuge - is it worth it?

[Todd]

I have a 36 gallon tank and have been thinking of adding a sump / fuge to it. Was thinking of a 20 G sump with baffles. Adding my heater, skimmer and calpura under a light, but no sand or liverock. The reasons that I want to do this are:

1. Add volume to the system
2. Get an in-tank fuge out of the tank (doesnt look so hot in there)
3. Hopefully solve a micro-bubble problem caused by my HOB skimmer

I have have a few questions about this though

a) Is the extra volume going to mean that I can add more livestock?
My nitrates have been good. I currently have 2 maroon clownfish, one coral beauty, one purple pseudochromi, small pearl bubble coral and a few fuzzy mushrooms, as well as a medium size collection of snails and crabs. I am hoping to add more easy to keep corals but also had thoughts of adding 3 green chomis. Does the increased volume mean that I can add more livestock, or am I 'out of room' in the tank?

b) I was planning a submersible return pump (Aqua Via 2300, ~ 380 GPH at 4 feet of head)
What does this do to any pod population from the fuge (it will be below the tank). Is anything going to survive the pump. Right now my in-tank fuge with Calpura has a fairly healthy pod population. I was planning on moving the calpura into the main compartment of the sump and light it with a screw in florescent light.

c) Is my skimmer going to be effective as a HOB unit on the sump?
Accessibility should not be a huge issue as I only have a metal stand, but I am worried that the lower water level will cause a lot of noise as the water splashes down (and salt creep). Also will it be alright to have the skimmer in the same compartment as the calpura if I protect the powerhead from it? On this same train of thought, will my heater be all-right in the sump with the calpura?

d) What is the possibility that the sump (20G with baffles) will not solve the microbubble problem and make it worse?

e) Is it worth the money to gain any of these advantages. As with most of you, I am way over my tank budget, and seeing as I am a student and a full time athlete dont really have alot of money to burn (wrong hobby). I do have a lead on a cheap sump and there is what looks to be a good 600 GPH U-siphon overflow on ebay for relatively cheap.


Thanks!

[TheReefGeek]

a) The extra water volume is going to "spread out" waste production across more water, so your nitrate leves will rise more slowly, everything else equal. If you add more livestock, and feed the tank more, you are going to get more nitrates overall, but lets say proportional to what you have now, because of the increased water volume. Now, you still have to deal with more nitrate reduction, because you are producing more nitrates. A better skimmer, or larger fuge would do this, so the benefit of a sump for increased bioload only really comes when you upgrade your skimmer, or make your fuge bigger. AND, livestock levels are also affected by the size of your tank, because happy fish need a little space of their own in the tank, or they will get more aggresive, so if you add more fish just watch that they get their little piece of the reef to sleep in and such. Also adding more live rock in the sump will increase waste reduction capabilities and allow a bit more bioload, depends on how much rock you have now as to whether you need it or not though.

b) Some pods will make it to your display. The advantage for pod levels is that in the fuge they are not eaten by your reef animlas, they are free to populate without predation. You might have seperated off your in-tank fuge for this purpose though. I would say if you are getting a bigger fuge out of the deal, go for it. I would add some live rock rubble and corse sand to the bottom of the fuge section to allow pods to grow there too.

c) Your skimmer will be just as effective, perhaps more so because you will be taking your top water off and bringing it down to the skimmer, and the top water in the tank has more waste than any of the other water, so you are skimming "dirtier" water. You do need to make sure that the water level in your sump is high enough for your skimmer to work still. If you have to lower your skimmer pump a bunch, and it has to push up against gravity, you will lose some skimming power. To combat this, you can install a baffled area tall enough to handle your skimmer. No problem with calurpa & heater & skimmer in the same section, just as long as you use some eggcrate or similar to section off the skimmer pump from sucking up calurpa. You could do the same to the heater, but most people put heaters in the return section to avoid this.

d) Microbbuble are solved by baffles in the sump, so if you have those, then microbubbles from the skimmer will not be a problem. Microbubbles can be created from the falling water though, or pushing too much water through the sump, such that the baffles are rendered ineffective. WIth your mentioned pump, this will not be a problem, but hopefully your sump has a baffle system, and place your skimmer before the baffles.

e) Yes it is worth it IMO, but caution has to be taken with u-tube overflows, make sure they don't lose siphone during a power loss, and keep them clean, and you have to pump enough water through them to keep air bubbles from forming (enough can form in the top of the u-tube that it will break syphon), with your setup this MIGHT be a concern, make sure you watch it closely.

[Todd]

Very thorough answer. Think that I am going to go for it. Thanks Rory!

[TheReefGeek]

Enjoy your sump!