i am a new beta fish owner and have been looking into a bigger tank. many of them have an under gravel filter. does anyone have an opinion on this type of filter? the reviews have had both good and bad things.
I don't use a UGF but from what I've read they are prone to clogging & are difficult to clean under which can cause problems with water parameters. Also keep in ind your Betta may not like the flow & it may be difficult to correct it.
Well, if the gravel is vacuumed along with the regular water changes, and once a month water is siphoned out via the up lift tube, you won't have the clogging. Ugf's when set up with a air stone and adjustable air pump are the least turbulent forms of filtration. This is just my opinion, I have been using them in small tanks for well over 30 years, with no issues.
I agree paloverde...UGF are great biofilters when properly setup and maintained.
They are old school...but so are we...lol....and we work fine as long as we are maintained...laffs......
Anyway, as paloverde has posted-deep weekly vacuum of the gravel will keep the UG-plates free of debris so they function properly. You are limited with type of live plants you can use since you don't want any plant roots to grow into the UG-plates and object that have a large base that cover too much of the floor-since that can impede water flow.
UGF's are NOT outdated -- there is no other filter that does the same thing -- it's a question of whether or not it's the right kind of filter for you. Every kind of filter has its advantages and disadvantages. Most of the tank kits that come with a UGF use an airstone and a riser tube to power the filter. Sponge filters can have the *SAME* setup. The way to deal with the current they cause is the same -- baffle the riser tube. I just stick a small bit of plastic plant in there and it diffuses it nicely.
In recent years, there has been a great deal of interest in natural planted tanks (NPT), which are basically not compatible with UGFs if the plants are the rooted kind. There are floating plants and non-rooted plants (like marino balls, actually an algae) that are fine with a UGF.
The nice thing about UGFs is that they are a very reliable and tried-and-true technology and you don't have to replace filter cartridges. They also circulate water throughout the tank very effectively, which helps keep the water temp consistant throughout the tank.
Cleaning with a UGF presents some different challenges, because as water is pulled up the riser tube by the air bubbles from the air pump, water in the tank is drawn down through the gravel (where beneficial bacteria reside) and under the filter plate. Waste accumulates under the filter plate and getting it out can be tricky. Some people use really powerful gravel vacuums on the riser tube and just suck everything out that way, which is convenient if you have a very large tank. Otherwise, the only other way to get at it is to take everything apart, which is tough in a large aquarium.
On the other hand, a smaller aquarium is much less difficult to work with. I have yet to try the vaccuuming the riser tube method on my 3 gallon because I am about to move, but I think it should work. My gravel vac has a squeeze-bulb (the $10 Top Fin one from PetsMart), so adequate suction shouldn't be a problem.
I do plant my tanks that have a ugf. I use a mix of gravel and pumice bits. The pumice bits are the secret to giving the bacteria colonies much more room to establish and keep things brewing away, if some of the roots form a mat. That said, yes I am limited to little or no hardscape, and try to keep the rooted plants down to few crypts, and some stem plants. You can have unlimited anubias , java ferns, and floaters.