View Full Version : Under gravel filter + plants = bad idea?

Bacallas Son
06-26-2011, 05:04 PM
Hi all,

I'm new to fish keeping, although my father has been a fish breeder since way before I was born so I've sort of grown up around it.

Long story short, I'm striking out and getting my own tank (29H) and I trying to build the most stable environment I can.

My father swears by under gravel filters for the stability that they can provide and says that most plants will grow fine in regular gravel despite lacking the normal substrates (which would be too fine to use with the under gravel filter).

Will regular gravel work ok for most plants or are there some I should avoid unless I'm willing to abandon the undergravel? Are there any substrates that would be compatible with an undergravel filter?

Thanks for your help!

06-26-2011, 05:48 PM
Plants and UG Filter is a no go! Just use a HOB Filter or even better a Canister Filter.

Plants need nutrients in the substrate to grow (roottabs or a nutriealized substrate (like flourish) or you can go the cheap way MTS "Mineralized Top Soil" (Organic Top soil washed and dried several times in the sun) with a cap substrate on top. With roottabs and flourish you have to dose your tank every day with Micro and Macro nutrients and CO2.
With the MTS you don't have to dose only have to add CO2 or exell (or another gluteraldehyde base product like metricide).

Read everything about plants and much more on "The Planted Tank Forum". http://www.plantedtank.net/forums/

06-26-2011, 06:01 PM
I have a 125 with an under gravel filter. I use pea gravel as substrate, but added finer gravel to it (smaller grained regular gravel) because some plants just won't stay rooted in the pea gravel. I seem to be able to grow most plants with regular gravel. I also have high light and added cO2 to the tank with the undergravel filter (maybe that helps). All my plants are growing in regular gravel. So yes, regular gravel will work OK for most plants.

06-26-2011, 06:22 PM
This came up on another forum. Someone actually tried an experiment comparing 2 tanks with and without UG filters. The UG tank plants did better. The speculated reason was better circulation of nutrients to the roots and less of a temperature gradient (no cold roots). The likely reason few planted tanks have UG filers is that the roots grow through the slits in the filter plates and tangle into one large mass. So if you like to rearrange your plants, it would make it more than a bit harder. If you are looking for a wild, natural look, it could work.

Bacallas Son
07-02-2011, 10:12 AM
Thanks guys for the advice - much appreciated

07-06-2011, 11:19 PM
I would also add that if you are looking for stability, then nothing short of a cannister filter can achieve this. I found that switching from a HOB to a cannister provided my tank with a more stable environment both biologically and in terms of adding CO2 since it helps prevent off gassing of any added CO2. You can try the UG approach but if you want to get serious about growing plants then you should eventually switch to a cannister. They also allow you to have a much neater look if you don't cover the tank or use a hood of any sort (i.e. you hang your lighting instead of using a hood or the short legs provided with most t5/cf setups).

Chris Noto
07-12-2011, 09:10 PM
I second all of the above. You've gotten great stuff already.

My two cents: I've done it, planted aquariums, that is, in any number of ways. I started out as a very young guy doing Very Old School, with no filter, incandescent light supplemented by sunlight, in an aquarium with a stainless steel frame and TAR (petrochemical!) for sealant. Then came the day where you "HAD to have UG filtration" if you wanted to do it right. :)

Now I've got PC Compact lighting, having not ascended to the level of the metal halide, T5, and LCD set. I've got CO2 in a tank, with a regulator and a pH probe. I can spin twelve plates on sticks, while playing Chopin etudes on the piano. No, strike that last one.

I've learned that if I'm paying attention, I can have a nice looking planted aquarium, using many different approaches.

Pick a "school of thought" that seems reasonable to you, and whose costs, in time and money, are within your reach. Pay attention to how things work, or don't work. Have fun. You'll do fine.

Holy Samosa
07-15-2011, 08:20 AM
You can definitely grow great plants with an inert substrate, as even plants that are considered to be heavy root feeders can pull nutrients directly from the water column. Thus pea gravel + fertilizer onto the water can work well.

Personally, I'd avoid an UG and go with a HOB filter if your on a budget and a canister if you have the cash to spend.

As for lighting, the daylight spectrum spiral compact florescents are a great option if you are on a tight budget and already have a hood with old school incandescent sockets. They are much better than the low output florescents that cone stock with many tanks.

09-21-2011, 02:21 PM
Just my 2 cents here. Almost all of my planted tanks have UG filters. I just know not to try to move established plants, so I go with the wilder look in the tank. My plants grow like crazy and I do not use CO2 anymore and fertilize once a week. I have a couple of HOB filters but mostly I have sponge filters in all of the tanks. This has worked for me for almost 8 yrs now so I am sticking with it. :) Lots of plants and fish in my tanks.