Bittabit
10-17-2003, 10:23 AM
I was sold a tank with a very cheap looking undergravel filter from Petsmart. I was wondering instead of traumatizing my fish and taking everything apart, can I run a second filter. If I can which I assume I can, what kind would be the best to run with and ugf. I don't want to spend a fortune, but I don't want junk either. Part two of my question is should I wait until the tank is finished cycling to install a second filter? Thanks again to all the resident geniuses that answer me...:D
OrionGirl
10-17-2003, 10:39 AM
UGF are some of the simplest filters to setup, and they are fantastic biological filtration. However, they must be maintained in order to work--this means vaccuming the substrate with each water change, and doing regular maintenance to clean out from underneath the plates. They do not work well with plants that go in the substrate, or large decorations that cover significant portions of the gravel, as both of these can block up the plates, and restrict flow.
A popular modification is to run the UGF backwards--have water pushed up through the gravel, instead of pulled down through it. The benefit is that solid wastes don't get trapped in the gravel. The downside is that you'll want to add a filter for mechanical filtration of these solids from the water column. So, if the tank is just been setup (less than 2 weeks with a standard fish load, up to 4 weeks with a light fish load), you can easily convert to a RUGF and add something like an Aquaclear for mechanical filtration. I am a fan of this method--the AC's are easy to clean, and you don't have to constantly replace the media. Plus, there are a variety of medias available. If you do this, vaccum the substrate very, very well--you may end up changing out 50% or more of the water, so plan on doing 2 days, back to back, before installing the reverse flow powerheads. Anything that is already in the gravel will be pushed out, and the tank will be cloudy and nasty until these solids can be removed.
Or, you can always just remove the UGF and install a HOB filter.