under gravel filter

I was thinking of doing an revers flow under gravel filter in my 55 fish only saltwater tank when I get it lined up to run again. Is there any pros or cons about doing one.

 

Cons = nitrate factory.... although most people say that anything is.
I would not recommend it though.

 

Reverse flow does not have any merit as far as I can see. The object of a plenum is to draw the water down through the substrate where it is filtered by the space underneath the substrate. To force the water flow up would not benefit the tank. This is just my first thinking, as I never heard of anyone wanting to do this. Why were you wanting to try this?

 

I think reverse flow would be worse. It would probably kick up sand and you would be sucking detritus down into the space under the gravel where snails and crabs would not be able to get to it and eat it. You would have to remove and clean under there often. If you have enough crabs and sand sifting snails I could see a normal flow under gravel filter doing some good but not the other way around. I would instead look into a reaction chamber that you can fill with gravel it will give the same effect but be much much easier to clean.

 

i set up a reverse flow on my 55g freshwater tank, its a congo terta tank with not a lot of gravel, the reverse flow worked great for the first two months. they it started to suck. needless to say i would not do it again. but i don't know if saltwater would be different, just my thoughts

 

This was just a thought, I done it with a fresh water tank many years ago and did not know if it would work in a salt setup. I just stay with the 4 inch crushed coral I have and a sump filter system. Thanks for the reply.

 

have a 15 year old 100 gal with a undergravel w/ clowns/damsels/hermit/cleaner shrimp all i ever do is stir it up and clean whatever settles most of the fish are over 10 years old.
no skimmer no live rock no sump just undergravel w/ 2 powerheads

 

There are successful tanks out there that use this method, most are older tanks like airtruck's. It's not used very often on newer tanks that I can tell so I personally would avoid using it just for the fact that it might be hard to track down lots of good information if you do end up having problems with it. JMO