anaeroby in deep substrate '

[magnosis]

I would like to rescape 20g planted tank, and want to do a mountain type of hardscape, something similar to this :



I wonder, is it necessary to run an undergravel filter to prevent anaerobic pockets (or other troubles) if the hardscape is very thick ?

For instance, this picture is from a 109g, I figure the hardscape must be at least 10" high in the middle/rear.  Is undergravel flow required to maintain this in the long term ?

[magnosis]

Anyone ?

I'm setting up the hardscape tonight, without undergravel filtering. I hope I won't regret it 

[dan2x38]

I researched this years ago but decided against it to much work I am to lazy... LOL They do it with terracing. On technique I thought was the best was to use Syrofoam under the gravel. It was siliconed in place. Then some gravel was silconed to the surfaces to cover edges of each terrace level. On top of the terraces you make your plantings.

Remember these tanks are pruned almost daily to look the way they do. Others are photographed right after setup when it grows out sell enough usually in the first weeks. What I am saying is they are a ton of work. 

Hope this helps somewhat. Google aquarium terracing for more ideas there are a lot of links for it.

[magnosis]

Thanks for the tips, Dan. I like this idea of using styrofoam. Just got to be careful as not all types of foam are safe for the aquarium.

And yes I agree, there's a huge difference in setting up an aquascape for show, and one that's viable in the long term.  I'm hoping for find a middle ground somewhere, but I know what to expect (or not to): in a year from now, it's quite unlikely my tank will look the way I plan it to when setting it up   We'll see, it's all part of the fun !

[dan2x38]

You can also use strips of glass or even acrylic as dividers and ways to hold back the substrate to create more terraces. You can even make boxes inside the aquarium with glass or acrylic just make sure they are water tight. Then you can cover them silicone wood, rocks or gravel onto them.

Another option is PVC pipe either on it's side or standing. There are many different sizes. By buying couplings you can get small pieces. Then silicone these into place.

Your imagination is the limit!

[rookie]

I would like to rescape 20g planted tank, and want to do a mountain type of hardscape, something similar to this :



I wonder, is it necessary to run an undergravel filter to prevent anaerobic pockets (or other troubles) if the hardscape is very thick ?

For instance, this picture is from a 109g, I figure the hardscape must be at least 10" high in the middle/rear.  Is undergravel flow required to maintain this in the long term ?

I was hoping someone would answer your question, as i`m also interested in the answer.

[dan2x38]

If you add that much substrate there will be a build up of (SO2) sulfur dioxide. Then if something disturbs the substrate at the lower level it will be released.

You might want to read up on deep sand beds (DSB). These are used sometimes in marine tanks as a way to decrease. One technique used is at 1.5" a layer of nylon screen like used on your back screen doors is laid. This prevents anything like in your case MTS disturbing the lower layer where SO2 forms. SO2 usually forms below 3" - 4". There is also a another technique Jaubert Plenum Filter.  I've been told the best solution when adding a DSB is to include a plenum. Google this and give it a read. If nothing else it will give you a better understanding of what happens under your substrate. Far as I know the principals will be the same for f/w as s/w for a DSB... someone will correct me if I wrong I am sure.

[magnosis]

Excellent advice as usual, thanks Dan

I played around with my hardscape yesterday, getting a better idea of how high I want it, and I sort of decided on building a plenum (that was before I read your post, ehe).

Petsmart sells undergravel filter plates, they are about 1/2 thick, perforated, and have tubes connecting to it for filter in/out.  I was thinking of using this, but rise it by 1-2", so I would have a 2" circulating water bed *under* the gravel.  I wonder if this pre-made u.g. filter mat will eventually get clogged by finer substrate and/or plant roots, but then again, I'm not planning on having big plants for in this tank (HC, HM, Starugyne and moss to start with)