question about live rock covering sand

[iHasFishes]

why is it important to not cover as much substrate as possible?
i have a 36g. and i have 55lb of live rock. and i'm having a hard time stacking the rock with just one row. and if i use two rows, it will cover most of the sand.

[StephLionfish]

Remember that when you add more rock, you lower however many gallons of swimming space you have. Just because a tank is 300g, for example, doesn't mean you can have any tang you want to if you have it filled with live rock- and no swimming space. I'd quit adding rock, if I were you.

[tmz]

Therare several reasons to leave some open substrate ,a few examples are :access by animals that need to bury in it or sift it; swimming space; areas where detritus and nutrients can sink into it; areas for upwelling and down ward flow; ovrall water flow; burying rock in sand it puts organics in it which can in low flow water be used by sulfate reducing bacteria creating sulfide deposits and hydrogen sulfide gas as by products.

You might consider putting some of that rock in the sump or an add on cryptic zone.

[iHasFishes]

http://i360.photobucket.com/albums/oo41/1reggie9/photobucket-3443-1322534069922.jpg
Well i only have about 30lbs in there. will that be enough?

[greech]

If you ever pick up a rock that has been sitting on the sand in one place for an extended period, you'll know why. Total weight isn't the ony thing to consider when evaluating how much rock to have in a system. Your rock looks fairly dense so while your weight suggest that you have enough, you are lacking the surface area that lesser weight but more porous rock provides (more surface area = more area for bacteria to colonize). Here are some good pics of dry porous rock...

http://www.marcorocks.com/150poundskeylargorockfreeshippinginthecontientialus.aspx

As far as you aquascape goes, a lot of your rocks are round which obviously makes is difficult to stack. I have taken a hammer and chisel to many of my rocks to get a better variety of shapes. No guarantees on how a rock will break but I have had good luck so far :).

[Ron Reefman]

That is 'enough' rock for filtration needs. How you stack the rock, or pile it up is a matter of your desire for a certain look. I set 90% of my rocks up on eggcrate that lays on pvc pipe legs just above the sand. Then some smaller rocks sit in the sand and trim along the edge hiding the eggcrate from sight. But I build my rock stacked up against the back wall ( I have pvc pipes and eggcrate back there as well). So I have the rock wall look with what looks like lots of rock. But there are lots of places to swim under and behind the the wall. This set up also makes for great water flow even under and behind the rocks (no dead spots at all - never had any cyano - ever).

[spieszak]

Ron - when you do the egg crate on top of the pvc followed by rock, do you have a constant dead spot in the pvc? Do you drill yhe pvc, or ensure its not completely covered by rock to prevent that? I've always wondered how that part works..

[tmz]

I also use plastics and pvc with plenty of perferations in it to keep the rock from settling deeply into the sand. Water will well up under the rock. As moving water strikes the obstruction the water pressure under the footprint of the obsturction is lower than the surrounding water leading to an upwelling and consequent downward flow to fill the void.This is known as advection . Reefs work that way with nutients welling up through them bringing nutrients for life. Think about how sand moves under your feet when you stand in the ocean.

[TucanSam007]

I like using potable epoxy to stack rock high to limit sand contact and dead spots/detritus build up. Depends on the rock though. With that dense rock you have you might have a an easier time drilling and using acrylic rods or pvc

[hollister]

You want the main pieces on the glass bottom and then build up from there. This will help stabilize the pile and reduce the chance of a glass breaking land slide.

I built a small box out of PVC and placed rock above it. Also epoxy helps and with big pieces you can drill two holes and use PVC to connect them.

55 lbs of rock in a new 33 gallon tank is plenty and will grow over time. Just remember to leave room to clean the glass and leave it loose so water flow can get around it.

Also fish will find a spot and call it home and defend it so have lots of over hangs and cubbies for them to choose from.

[iHasFishes]

an egg crate is a great idea! thanks a bunch guys! great info:)
Greech, if you look close you can see the one rock, i broke into 3 pieces. (that top left rock and the rocks sitting diagonal to it.)
This rock is very round, and heavy. get what you pay for! got it for $1.50/lb online. uncured. took 6 weeks to cure:/ Never again! I have some BRS dry rock that showed up this morning. it's soaking in vinegar right now. when it is cured, i will either add to it or replace entirely. i'll update this thread with pics when they're added:)

[aleonn]

I also used eggcrate, as well as PVC structures to hold rocks in place. I drilled each rock to slip 1/2" PVC. In earthquake-prone CA, I wanted to minimize rock avalanches!

Looking forward to pix, good luck with the build!

[iHasFishes]

^^thanks! Also if anyone using egg crates i would love to see some pics of you get a chance.

[aleonn]

My eggcrate is covered by my 2-4" of sand. I got it from Home Depot under the lighting section (sold as lighting diffuser).

[iHasFishes]

ok, how far does the egg crate stick out of the sand?

[r-balljunkie]

is that texas holey rock, or live rock? eventually, you might consider trading in a few pieces for something more shelved, or oblong shaped to make scaping a bit more manageable. your kinda stuck with a bucket of softballs, trying to make it work. it takes some time to get the look you want, and dont feel like you have to use all of what you have on hand. i have a few pieces relegated to the sump personally.

good luck......you'll get the look you want soon enough.

c

[aleonn]

Eggcrate is maybe 1/4" thick. It'll be easily covered by sand.