undergravel filter or not?

Hello,

I am pretty new to all this & this is my first post so please bear with me. I have just bought a 40 gallon tank (second hand ex display) which has an under gravel filter as well as an internal terratec filter. I am setting up the tank for Tropical fish. The guy I bought it from advised me to use them both as the under gravel filter helps to keep ammonia levels down. I have read a little on these filters & there seems to be a bit of a mixed debate as to whether they are good or not. I am not sure if I like the extra tubes in the tank as they don't really look natural with bubbles racing through them. I am also wanting to plant the tank up quite a lot & have heard that with UGF's roots seem to be bigger than the plants (which is not the effect I am after). Some advice would really be appreciated, thanks.

 

First of all, Welcome to Fishlore.

UGFs create a lot of extra problems, in my opinion. They are not necessary. I have one running in one of my tanks, but it has a powerhead rather than an airstone. The powerhead has a much greater current to it, so it does a better job of keeping the space under the filter plate clean.

 

Thanks sirdarksol,

from what I have read, it pretty much seems the opinion of most that they are not good. I don't think I will put it back in when setting up. How do your plants get on with a UGF?

 

I have no rooted plants directly over the UGF. It's in the center, while the few rooted plants are around the edge. Most of the plants in that tank are tied to the driftwood.

 

Welcome to Fishlore.

All of our tanks run with HOB filters.

 

I'm going to go with sirdarksol here, UGF are outdated. They're just bad all around if you plant to use them with airstones...and at best don't do anything when using a powerhead...so they just clutter up the tank and complicate maintenance.

Modern filters provide sufficient biolgical filtration to get rid of he UGF (which only does biological). Back in the day I guess filters really weren't that great, so the UGF was almost essential.

 

at best don't do anything when using a powerhead...
[/QUOTE]

Not true. A UGF does provide a lot of biological and a bit of mechanical filtration with stuff that's already in the tank anyway (presuming your tank needs a powerhead). A power outage can kill the nitrifying bacteria in a filter if it lasts long enough to let the media die off. The nitrifying bacteria in the substrate take a lot more than a few hours of power outage to kill.
The gravel has far more surface area than the floss in most HOB filters, as well. (Also, these filters don't really have much more surface area than before. I have a really old Tetra Whisper that has the same setup as modern ones)

Even with the airstones, UGFs do this, but have the problem of getting gunked up.

This is why I chose to put a UGF into my molly tank. (It also helps that I can turn the internal filter off if the mollies breed) There's never anything wrong with extra filtration, and a UGF definitely offers extra filtration.

 

Thanks again for your comments, sorry I haven't replied sooner but just been busy with the kids. I 'think' I have decided to just use the Terratec filter now. Mind you, the guy next door (who also keeps fish) is trying to convince me otherwise. If I am honest, I didn't really wish to use it in the first place as I think they look a bit naf with the bubbles going up the tubes (reminds me of some 80's clothes shops) I want rocks & plants (lots of plants) & two one inch plastic tubes with bubbles rising through them doesn't really fit in anywhere in the plan. Thanks again

 

Excellent reasons to not get a UGF.

 

at best don't do anything when using a powerhead...

Not true. A UGF does provide a lot of biological and a bit of mechanical filtration with stuff that's already in the tank anyway (presuming your tank needs a powerhead). A power outage can kill the nitrifying bacteria in a filter if it lasts long enough to let the media die off. The nitrifying bacteria in the substrate take a lot more than a few hours of power outage to kill.
The gravel has far more surface area than the floss in most HOB filters, as well. (Also, these filters don't really have much more surface area than before. I have a really old Tetra Whisper that has the same setup as modern ones)

Even with the airstones, UGFs do this, but have the problem of getting gunked up.

This is why I chose to put a UGF into my molly tank. (It also helps that I can turn the internal filter off if the mollies breed) There's never anything wrong with extra filtration, and a UGF definitely offers extra filtration.[/QUOTE]

Good points, I guess it just depends on what you're going for. I have battery backups on my tanks that can operate the filters for 6 hours during an outage...but that's just me, my power company plays a game called "random blackouts for no reason." It's really a lot of fun!

(the heaters aren't on the battery because 1. the straight draw would flat the batteries in a few minutes and 2. the tanks don't cool very quickly anyway...about 4 degrees in 6 hours).