Need Advice on Live Rock stack

[JohnnyM2]

I am in the process of setting up a new 90 gal Oceanic reef tank with overflow. I have a two inch sand bed, 100 lbs of Vanuatu and Uaniva live rock (dense but very pretty) and 40 lbs of Marshall Islands live rock. Almost all are very large pieces. The smallest is about 8" diameter and the largest are nearly a foot square or elongated (up to 18"). I currently have lots of flow (600 gph from my return, a Seio 820 and Seio 600 plus a maxijet 400 that I had lying around. I plan to replace the maxijet with a more powerful Hydor Koralia (just for fun and to try it out). Win setting up the live rock, I had several goals:

1. staying far enough off the glass to allow my magnet to get everywhere.
2. no rock touching the glass, even in the back.
3. a stable stack without adhesives
4. a natural look

I don't know if these are really the right goals and I have ended up with a stack that ends just inches ( in some places 1") from the top of the water column. My stack is also as far from the back wall as it is from the front wall. Although the stack looks good, it somehow does not seem right after reviewing many pics of "tank of the month" for the past year. I want to have lots of corals (lighting is two 10,000 K 150 watt MHs and two 96 watt actinic PCs installed in the canopy as a Coralife Aqualight Pro retrofit kit) and I plan to have about half a dozen fish.

Should the stack be allowed to touch the back wall to leave more room in front? Do I need to reduce the height? Does anyone have a more intelligent set of goals for creating the stack? I really could use some sage advice. Thanks.

[oli5]

Do you have any pictures?

[JohnnyM2]

Here is a picture (I hope)!
http://reefcentral.com/gallery/data/500/124426New_90_gal_Tank-thumb.JPG

[BrianCM]

Have you tried using pvcp as support then stacking rock around it. Also have you thought about making shelves with the rock.

[JohnnyM2]

Anyone have any advice?

[Frick-n-Frags]

I can usually shuffle a pile of rock around until it sits very solidly.
Maybe it takes a restart or two.

I do it on a BB tank, sand should be easy

there is no law against breaking an unmanageable piece of LR into smaller pieces either

[saltydude]

FRICK; I wish I would have thought of that when I first set up my tank. That is great advice!

[kevin gu3]

Why do you not want the rock touching the back glass? Can you see in from both sides?

[davocean]

Keeping rocks off the back glass allows for circulation.
I do the same, and also try to keep it so I can clean easy.
Hard to tell from small pic, but looks OK.
Only thing is rock at top 1" from surface can't have anything on it, and you need to watch water level.
Have you seen REEFVIDEOS.COM article on pegging?
I'm about to do that myself this weekend.
Then you can move things as needed.

[kevin gu3]

My favorite method involves a cordless drill, masonry bit, and zip ties.

[davocean]

Zip ties work, but I've found that alot of times you have to move things for light or flow issues.
And you may not like the first scape you make.
With pegs, you just pull up whatever and move it, just like that.

[zach0660]

I created pvcp supports and stacked the rock around it. It also allows for more flow.

[useskaforevil]

you can make a wide base, attach acrylic rods to it, drill holes in your rock, and fit them ontop of the rods. and nothign is wrogn with the height, 'll jsut bet nothing wil utilize that height.

[JohnnyM2]

Kevin, as davocean points out, I am trying to allow for good circulation, cleaning and positioning small powerheads behind the reef. Not saying thats the way to do it. Just feeling my way along here. Also, davocean, thanks for the reference to pegging, I will look at that next. Thanks to everyone else for the helpful advice. My big concern though is if I stack and secure the rock like this, is it good or bad? Will it cause me problems down the road?

[kappaknight]

You can actually have some rock touching the back glass and still have good circulation. My rocks are currently touching the back glass on the upper part, but I've left a tunnel on the back botton for the whole width of the tank. Also, the way I stacked my rocks has tons of tunnels and holes so flow should not be a problem.