Undergravel filter or not?

I will soon be moving into my new place and was wondering what your thoughts were about putting an under-gravel filter in when I move? Also currently using a mix of playground sand and crushed coral, whats your thoughts on this mix? Should I switch to just live sand or just crushed coral? Currently not having any problems, other than hair algae, but wanted to see if anyone else had any input since the tank is being disassembled anyway.

Thanks,
Dustin

 

I have an undergravel in my 45-gal FO marine tank. I think the concept of what the UG does is sound, and applies to marine tanks. But other websites say that the undergravel is a throwback to freshwater fishkeeping and should not be used. However, except for the concern of the UG getting plugged up with detritis and creating anaerobic zones, I haven't seen specific reasons for not using one in a marine tank. Other thoughts?

 

nah

SAW39 is correct, a UG is considered a blast from the past. You have to understand why other systems have come about. It’s because they are better! We have learned much in a quarter century.
Although a UG is an efficient freshwater nitrate factory just like the wet/dry, it restricts the other types of filtration available to you. The sump setup allows one to use a DSB or live sand/crushed coral etc substrate, which has multiple benefits in saltwater such as denitrification and buffering. You cannot use these finer materials with a UG. At best you might use a coarse grade of coral or dolomite, but this reduces buffering effectiveness. If you use a UG with live rock to resolve the nitrate problem, then you end up significantly considerably reducing the UG’s effectiveness. For several reasons among which are; rock itself and the weight of rock on UG restricts flow. You could of course try a reverse flow UG to reduce some of the negatives but that neglects the many positive aspects of newer systems utilizing sumps and overflows, such as water level control, protein skimming, heater hiding, refugium, chemical filtration, chemical addition, filtration hiding, etc. Info which is readily available on the net should you be so inclined.

In conclusion, it is usable if money and/or effort are lacking however its like driving a 60's vintage car on today's superhighways. It is just not going to be as efficient or effective.;D

 

Well said!!

 

Thanks All,
I am currently using a wet dry in combination with a refug (only 10 gallons), protein skimmer, UV sterilizer, and 110 lbs live rock. Just thought since i had the underground filter from my old set-up (freshwater) I just thought I would see what the opinions were here. "The Conscientious Marine Aquarist" By R. Fenner, does not "destroy" UG filters just mentions that they have drawl backs and that they run better in reverse. Just thought I would ask.

Dustin

 

Thank you, Big Wally B.