Question about rocks for Malawi tank..

[A1cntrler]

I have tried my luck with a 29g Malawi tank, and loved it, but want more. I got the go ahead to get a 55g to display downstairs in out house. ( I think seeing my brother 55g Malawi really sealed the deal) So I am keeping an eye open on Craigslist for one to come up cheap. There are a lot on there that is for sure, but for what some want for them, I can go buy a new setup.. Anyways..

I want to have a lot of rocks in there for them to swim around. I saw a photo of a Malawi tank the other day (can't find it now of course) that had a sandy bottom with several rocks mixed in, and it got rockier going from left to right, with a tall rock mound, maybe like 12" tall and rounded top. Now I don't want to put that many rocks in there for weight reasons. All I need are the rocks that can be seen that make up the outer part of the mound. There is a nursery around the corner that always has a lot of nice river rocks/stones from around the country (even sometimes some Texas Holey rock!) I had thought of building a wire frame to attach the stones to, but then though with it being hollow, some fish might get lost in the middle and want to live in there indefinatley. The I had the thought to use some lava rock for the inside, with the river stones on the outside. What do you think of that?? I do remember science class when the lava rock floated though.. How would I secure it together and hopefully have it sink and remain there?? I have read the silicone may work, but is sometimes difficult to get it to stick to some rocks. What are your thoughts on hot glue? Thanks for the input!

I'm sure my son will be disappointed to see his fish move downstairs, but I'll move my 10g Tropical Community into his 29g in his bedroom, put the 55g in place of the 10g, and put the 10 on Craigslist....

[Drumachine09]

Silicon and lava rock stick great. I stuck a ton to a piece of scratched up plexi glass. I don't know if mounting to plexiglass would be practical for you though.

[A1cntrler]

Plexi may be a good option instead of it right on the glass. I was going to put a light diffuser (egg crate) under the mound. Probably will need a lot of Lava rock tho... I saw some big bags at Lowe's the other day for landscaping.. I guess a good boil on the stove would help clean it up some...

[Drumachine09]

When I did it, I just put half of it in a bucket in the street, and went to town with the hose. It was clear as all getup, and nothing came off when I put it in the tank.

[Ellen4God]

Okay, so I'm not very experienced with this stuff, just thought of something that I've read on the forum somewhere. Could you use stirofome (I have no clue how it's spelt) as a base for the mound? I know people use it for backgrounds and such. Could you get like a block, cut it to the shape you want, and then attach rocks to that? Just an idea!

[A1cntrler]

Only problem with that is that it is rather bouyant. A small block of it could hold my fat butt up in the River Raft race here a year ago, so I would imagine to get enough rocks to weigh the foam down, It would be overkill. What I needed was a lightweight , non floating filler to make up the unseen part of the mound, and I think lava rock will do the job. I'll get some to play with and try it out though.

[Ellen4God]

Oh yeah. I didn't really think of that! lol

[snipers_den]

i made a rock wall out of pvc rain gutter...zip ties....black aquarium silicon...and lots of lava rock.......takes a long time...but it sure looks nice....cut some holes in the pipes too make caves for them to explore but put in some dividers for seperate fish condos.......also use some disposable gloves