Aquascape questions

[Ab129]

Ready to get my rock and design my scape.
How much space should I leave between the rock and the glass?
I'm thinking 2.5 inches?
Also, how important is it to build a base for the rock and what materials should I use? Egg crate seems simple enough but I have read that many advise against it.
I will probably have a 3-4 inch deep sand bed.
Could I maybe put 1/2 inch sand under the rock base or will that eventually shift.
Thanks for any advice.

 

[Diana A]

Never place rock on top of sand. If the sand shifts, the rocks will tumble. IMO 2.5" from rock to glass is kind of close. You need to have enough space to get in there to clean the glass...can you do at least 3"?

 

[ReefEco]

Hey there, depending on how big your tank is, I would leave much more space than 2.5" to the glass, for easier cleaning, space for corals to extend from the rock, and for water flow around the rock/corals. If you are working on a small tank, 2.5" might be in proportion to what you are working with, but I'd go larger if you can.

3-4 inch sand bed is too shallow for a true "deep" sand been, and too much to not cause problems down the line. I would advise 1-2 inches if your goal is aesthetics, or 5-6 inches if a DSB. Most people don't use DSB any more, or install them remotely due to the sheer amount of space they take up in the tank. If you have wrasses or other substrate-oriented fish, 3-4 inches might make sense.

As to what to put your rock on - definitely place it on the bottom of the tank glass, not on any sand, then add the sand around it. Eggcrate can be used, but will prevent easy movement of detrivores and possibly trap nutrients within the squares at the bottom of the tank. I'd stay away from it. Depending on how much weight you are trying to distribute, ideally your rock work would have minimal contact points with the tank bottom, and be elevated above the level of the sand so detritus, which collects at the sand-rock interface, is minimized. So, if you can elevate your rock structure off the tank bottom using a couple of "pillar" rocks that, even when you add sand, still create a space above the sand - that is ideal for flow. I've even sliced rock to make a flat bottom, and siliconed the rock directly to the tank bottom.

Hope that helps!

Best, Peter

 

[ClownNut]

4" min. for fat hands.
sand i would recommend 1 or 6+. better yet do BB. but if you do sand, rock should sit on something solid. you can cut some pvc pipe to have the rock sit on and sand will cover that up.

 

[Frank H]

Rocks directly on bottom glass, and 3 inches from sides works for me as long as its low in the tank. I have one spot where rock is closer to 2 inches from side wall but its so low that I can reach the bottom for cleaning glass when I need to.

 

[Ab129]

Thanks for replies!
Tank is 75 gal. I will go with 1-2 inches of sand
My vacuum tube is 2 inches in diameter so would 3 inches be ok for spacing?
I will not be building rock walls so the 3 inch spacing will be the closest and only at the bottom where the rock meets the sand. There will be more space between rock and glass the higher up I go toward the surface.
And I'm a little confused about the pvc stand/base, what would that look like?

 

[Diana A]

You can get quite good flow under a rock pile if you set it up off the sand on an egg crate platform set on pvc legs. 95% of my rock is 1" to 2" above the sand or Bare bottom.

 

[Diana A]

Here is a shot of the back of my 10 year old daughter's tank. You can see the pvc legs and the eggcreat

 

[Ab129]

So it's ok to use the egg crate just don't put it directly on the bottom?

 

[Ron Reefman]

So it's ok to use the egg crate just don't put it directly on the bottom?

Yes.

Check out my build thread and you can see how I did it. Link address is in my signature below. My old 180g tank was the same way for 6 years.

You get water flow under the rocks, better for good water movement and cutting down on dead spots where cyano wants to develop. The bottom of the rocks can grow bacteria, sponges, feather dusters and more when they aren't stuck in the sand. CUC and wrasses have lots more sand surface to work on and use for hiding. Critters that want to hide out have all kinds of space under the egg crate. It only takes a small amount of rubble to fill in along the edges and hide the egg crate.

I have a 125g and only 5% to 10% of the sand has rock sitting on it. I have 2 8" to 10" yellow sea cucumbers that I only see once every 4 to 8 weeks as they spend most of their time working sand under the egg crate. I haven't found a single drawback to getting the rocks off the sand!