The Ultimate DIY Rocks!

[skey44]

probably too much cement too much water combo.. i don't know i just did some and i submerged them after overnight cuz the mold boxes got rained on during the night, hopefully they hold up, i think i mixed the cement pretty dry and used very little cement. next time i think im gonna use just enough cement to hold the aggregate together no more. this time i think i did 1 part cement to appx. 3 times other (OS, aragonite, salt)

has anyone used dolimitic calcium? i used this on the underside of one of my rocks and it looks ok a bit too uniform but a good mold material for the base.

 

[customcolor]

i found out too that the portland salt mis is week after 1 day but i was just realy carfull(only broke 1 big peice) and i put it right into water that day. after 3weeks of dayly water changes it was ready. i just put in a few peices in to my tank 3days now

<a href=showthread.php?s=&postid=9361810#post9361810 target=_blank>Originally posted</a> by kraze3
I used the quikrete portland type I. Grey bag. I let my first batch dry one week without touching them at all and my second went two weeks. Both batches seemed very strong and sat in tubs in my backyard for leeching. After being in my tank for about a week they all slowly crumbled. theres nothing left of them now. So Im looking to try a new kind of cement.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9358274#post9358274 target=_blank>Originally posted</a> by Travis L. Stevens
The reason is because the WWM version of rocks is the old oyster shell/sand/cement mix that lends very little porosity to the rocks even when done correctly.

Wow Travis. That is a very incorrect assumption, and I can't believe you were the one to say this. I will try to keep this from being "flamey", lol - 'cuz I like you.
:smokin:

First off, cements without polymers or epoxies are already porous, to a certain degree. Google: cement chemistry porosity capillary
if you really want to know about this - these terms should get you in the right direction anyway.

Until I found this thread, I had been making rock by the "WWM/GARF" method/recipe. I've very rarely made nonporous rocks, and most of my rock was more porous than the real thing. The rocks I made are probably not as porous as your rocks are, Travis, but I bet they come pretty darn close.

GARF has been in business for what? 15 years? More? Selling MMLR that convinced a lot of the USA reefers that MMLR was a decent substitute for real LR. Aquariums use the old method of rock, or more recently, some are using "sprayed" cements.

MMLR by the "old" methods does take skill and finesse to make really, really porous rocks - unlike the salt:cement only recipes which allow even idiots to make round ball rocks that are porous.

I've also never made a batch of rock and had it disintegrate during kure. Cement is designed to act as a glue between aggregates, and in this case, salt can't be considered an aggregate - so there is really nothing for the cement to form a bond with. Cement and salt rocks do work, but considering how many folks are reporting "They crumbled", during kure (and it happened to me - I tried them too), do I really want to risk these in my tank? Or to risk my reputation on selling these to others? Not really.

It comes down to a choice, really, since we are mostly only guessing that more porous rock is better - very little true research has been done on the matter. One can use an old, tried and true method, and not have to worry about if the rocks are going to start disintegrating in one's tank tomorrow, next week or in five years. Or one can be a more pioneering spirit, and try the new method of rock, which certainly has potential, as it is so very economical to produce, and easy to work into interesting shapes. But except for Travis himself, very little research has been done with this type of rock, so a certain amount of "trial and error" is to be expected.
I'm a fence sitter, lol. I'm ok with my rock not floating - I'll use salt in my mix, certainly, but it will never be the only thing in my rocks.

The "trickle test" is a nice way to see how porous your rock is. Take one cup of water, in like a measuring cup, and pour it slowly into/over your dry finished rock. It should take about 10-15 seconds per inch thickness of rock for most of the water to exit on the bottom side. If it did, your rock is more porous than 75% of true LR. It isn't very accurate, I know, but a guy on a BBS (remember those old folks?) many years back had posted this, and it does seem to work for a gauge, at least for the ol' skool rock, lol.
And a side note on the Trickle Test - most true LR will shed a third to half the water off its surface before any seeps in to trickle through.


Im done ranting, but I had to for ol' skool rock honor, man...

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9353017#post9353017 target=_blank>Originally posted</a> by Rhodophyta
The acid in the leaves neutralizes the alkalinity and stain parts of the rock various shades from gray to brown, giving it a natural look.

Ah yes. I discovered this:

when the snow and ice melted last week. I forgot to bring in the last few pieces I did last fall, and discovered that DIY rock will disintegrate if frozen, lol.

But the leaves stained the white rock/crumble really dark - I will scavenge this stuff to use as aggregate in another batch and it might be pretty cool looking

Does it really help with Alk?

 

[Barto]

I have some that are still submerged & frrrrrozen in a tub.
Don't know if I should wait for the spring thaw or bring the tub into the basement. Garage is not heated
What I can see thru the ice looks like they're in one piece

 

[Insane Reefer]

Expect an Algae Bloom...

Expect an Algae Bloom...

Ok.
I now have the beginning photos of fresh, kured MMLR in a system.

This first photo is the cycled seed tank, and my future quarantine tank. A standard 10g with 18w of 50/50 T8 (HO), HOB power filter and powerhead. I took half the sand from the tank, from the left side only, and a single rock, as well as a bunch of rubble that is hidden in a rear compartment on the Biocube. I last cleaned this 2 days ago, and this photo was taken today.

This is the Biocube 8, with MMLR back-wall made by yours truly. Granted, not the model tank for an algae bloom test, but it is what I have, lol.

It has 18x2w PC lighting. The rock wall was made with white portland, sand, OS and CC - no salt. It was not made to be porous, only solid. This is the first day it is setup with saltwater. Don't you love my "Monty Python" foot rock - it is real LR! :lol:

By day 4, I had a very healthy bloom of diatom - pretty much only on the back-wall. A little bit in the corners were flow is poor (will be mod'ing this tank with a "Y" on the return and a higher cap. return pump)

I will continue taking photos in 4 day increments, for the next 2 weeks or so.

Today is day 6 - the diatom is starting to recede a bit, and green film? algae is starting under the diatom bloom - hopefully the next photo will show that.

 

[Rhodophyta]

I am wondering if those who are not willing to cure their cement rock for 28 days before submerging it, or concerned with crumbling and excess alkalinity, whether due to rushing things or not, should try something "instant".

Resin mixed with aggregate will produce rocks that can be used the next day. If the aggregate is coarse, the resulting product will be porous and the knobbly surface should coat over anyway with coraline.

Carving sintered glass or ceramic foam would produce rocks that need only be rinsed of dust and used as soon as you are happy with the shape.

 

[ebe]

I am no concrete expert but from my readings, the strength of the concrete comes from the bonding of the cement to the aggregate. If the rock is only salt & cement powder and if the salt truly does letch back out of the rock when kuring, where is the strength? Years ago I made my current stand of DIY rock using the crushed oyster shell to cement mix and these rocks are still very much rocks today and have coraline, sponges, feather dusters, etc growing on them. I made a batch for my brother's cichlid tanks and you need a hammer to get them to break. My latest formula using crushed oyster shell and southdown sand to cement are, in my opinion, even stronger. I am experimenting with just using solar salt as molding material and pressing it into the outsides of the rock.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9385558#post9385558 target=_blank>Originally posted</a> by Rhodophyta
I am wondering if those who are not willing to cure their cement rock for 28 days before submerging it, or concerned with crumbling and excess alkalinity, whether due to rushing things or not, should try something "instant".

That is one of the nice things about the Ol' Skool mixes - I typically allow them 3-4 days in the casting box (unless it is something delicate, which gets different treatment), then they go directly into the kuring barrel/bin. They never fall apart when I do it this way.

Although I am going to make up a batch and leave it out dry for the 14 days recommended by Quikcrete, without removing the salt or anything, to see if money can be saved in the kuring process, as maybe this will reduce wet kure time, 'cuz DAM, water is expensive, lol.

 

[GuySmilie]

Travis, I think it was you awhile back who mentioned that you're next wallscape was going to be built on eggcrate, then attached to the rear glass wall. I assume you are going to silicone seal the entire perimeter for the wallscape to the glass?

The reason I ask is, I'm thinking along these same lines for my newest tank, but I thought about just 'tacking' the wallscape onto the wall with a few choice blotches of sealant. But then I got to thinking about how stuff would accumulate between the cement panel and the glass. And this would be no good.

What was your thoughts on installing an eggcrate-backed panel to the glass wall? Thanks!
Guy

 

[Azazael13]

First attmept done over the weekend. I already know one will come out looking funny since I didn't think my great casting method through.

Thought process:
1) Hey this box would make a perfect casting box.
2) Lets put some oyster shell in the bottom.
3) Put this little bag here to create a cave.
4) Fill the box up.
5) Let sit fora day.
6) Oh crap I am gonna have 4 walls that are smooth. DOH!

Once the first mold cures can I add mix to the already flat sides to change it? IE will anything added to the sides now be connected, or do I need to epoxy it some how.

My wife (civil engineer) also found a fair amount of humor in my first batch of mix. Something about how I may or may not have maybe had a little too much water in the mix

Oh well, for what I spent on materials, I can afford to mess up a batch or ten

 

[Rhodophyta]

<a href=showthread.php?s=&postid=9396809#post9396809 target=_blank>Originally posted</a> by Azazael13
....

My wife (civil engineer) also found a fair amount of humor in my first batch of mix. Something about how I may or may not have maybe had a little too much water in the mix ....

New hod carriers always put way too much water in the mix. You are not making cake batter. More like a super stiff icing.

Why not try taking off the smooth edges that show with a cold chisel, or concrete tools less primitive or more primitive than that? If your mix was a little wet, the concrete won't have much strength and this should prove easy. One other "new hod carrier" problem not addressed much here that causes rocks to disintegrate is overworking the mix. Once the concrete has begun its true set, you have to STOP. If you keep working the mix, it will lose cohesion. A good brick layer will take one glance at bad mortar and dump it. And tell you what you did wrong or let you figure it out by trying again. We don't have any feedback like that so when rocks disintegrate we think about the mix, the cure time, etc. anything but that we didn't know when to stop adding water or when to stop working the mix. You may learn something just by chipping away at your rocks.

Maybe save one smooth side for the tank bottom.

 

[rsteagall]

A friend of mine just bought a used 75gal RR oceanic. I've convinced him to take his time on everything. He's actually wanting to make his tank appear to be Greek Ruins or an Atlantis type scene w/pillars. I'm certain we'll be using this and methods like it for doing everything. Has anyone done such? If so, please post pics or a link.

Thanks,
Ryan

 

[kraze3]

Yea i messed that up travis caught it

it was salt:cement 2:1 and 2:1.5

 

[Travis L. Stevens]

<a href=showthread.php?s=&postid=9387334#post9387334 target=_blank>Originally posted</a> by ebe
I am no concrete expert but from my readings, the strength of the concrete comes from the bonding of the cement to the aggregate. If the rock is only salt & cement powder and if the salt truly does letch back out of the rock when kuring, where is the strength? Years ago I made my current stand of DIY rock using the crushed oyster shell to cement mix and these rocks are still very much rocks today and have coraline, sponges, feather dusters, etc growing on them. I made a batch for my brother's cichlid tanks and you need a hammer to get them to break. My latest formula using crushed oyster shell and southdown sand to cement are, in my opinion, even stronger. I am experimenting with just using solar salt as molding material and pressing it into the outsides of the rock.

I'm not an expert either, but a 250lb man bouncing on it, and repeated hammer blows to break on open that was made from the Cement:Salt recipe is strong enough to put in my tank.

<a href=showthread.php?s=&postid=9395224#post9395224 target=_blank>Originally posted</a> by GuySmilie
Travis, I think it was you awhile back who mentioned that you're next wallscape was going to be built on eggcrate, then attached to the rear glass wall. I assume you are going to silicone seal the entire perimeter for the wallscape to the glass?

Nope. It's going to be eggcrate attached to a PVC Frame. Look here for more details: http://reefcentral.com/forums/showthread.php?s=&threadid=875880

The reason I ask is, I'm thinking along these same lines for my newest tank, but I thought about just 'tacking' the wallscape onto the wall with a few choice blotches of sealant. But then I got to thinking about how stuff would accumulate between the cement panel and the glass. And this would be no good.

For my tank, there will be high amounts of flow, and I don't mind the "dead" spots. This is a perfect breeding area for various zooplankton, sponges, etc. It's what I have on my 29g, to an extent, and I couldn't be happier.

What was your thoughts on installing an eggcrate-backed panel to the glass wall? Thanks!
Guy

For those who know me, they know I'm a cheap reefer. They also know that I like to get money wherever I can. Personally, attaching the eggcrate to the glass would just decrease the resell value and if you ever got out of the hobby, it would be difficult to sell or even move the tank. This is why my back is going to be on a PVC structure and the rocks will be ziptied to them.

 

[sunkool]

the backdrop on my 125 is one solid peice of liverock

I did this with white tile grout it is 2" thick.
it took 3 weeks to do and cost $40.00 but was well worth the time.
the way I did it was to lay the tank on it's face set up the mold made out of 1/2" plywood. I put potting soil down in the mold (for texture) mixed the tile grout on the wet side, and poored it on top of the soil. let it dry for 5 days. the hardest 5 days of my life.
then with 3 of my friends we lifted the tank upright.
now for the fun, shopvac the soil out of the tank. the soil still had moisture in it so I let it dry out for a few more days.
then I used the vac again to get as much of the soil out.
the remainder had to be scrubed out with the tank filled with water.
the hardest part of the hole job was moving the tank in to the house as it was like having a 200lb peice of rock in the already heavy glass tank.
It is now covered in purple with tube worms trying to take over.

like I said hard work but well worth it

 

[eameres]

After seeing what you guys have done, I'm starting to think that disguising 2 megaflows as rock might not be so daunting! I was avoiding them like the plague, but this may actually make them more easy to live with!

 

[Rhodophyta]

<a href=showthread.php?s=&postid=9395224#post9395224 target=_blank>Originally posted</a> by GuySmilie
Travis, I think it was you awhile back who mentioned that you're next wallscape was going to be built on eggcrate, then attached to the rear glass wall. I assume you are going to silicone seal the entire perimeter for the wallscape to the glass?

The reason I ask is, I'm thinking along these same lines for my newest tank, but I thought about just 'tacking' the wallscape onto the wall with a few choice blotches of sealant. But then I got to thinking about how stuff would accumulate between the cement panel and the glass. And this would be no good.

What was your thoughts on installing an eggcrate-backed panel to the glass wall? Thanks!
Guy

Eggcrate would be a poor choice since it wouldn't adhere to the concrete and silicone does not stick to it either.

If you used a coarse Matala filter mat, the concrete would be caught in the weave, the mat would give strength so you would not need to make the concrete thick at all - the texture could be carved in the front of the mat, the mat could be siliconed to the back but would be easily removed later if you ever decided to.

 

[Ball]

<a href=showthread.php?s=&postid=9400315#post9400315 target=_blank>Originally posted</a> by Rhodophyta
Eggcrate would be a poor choice since it wouldn't adhere to the concrete and silicone does not stick to it either.

It really doesnt matter if concrete does not stick to the eggcrate. Once it hardens, the concrete all bonds to itself. It not like you can take out the eggcrate or it will jar loose from its prison inside the concrete. Same thing when building around pvc. Its just to make the initial shape and maybe provide some stength afterwards like rebar in a driveway.

 

[Insane Reefer]

And as to "what silicone will stick to", silicone IME will stick to almost anything - the problem is how tough a bond it makes.

My Biocubes backwall is made of ABS, and a few stated that I would have problems gluing my pieces to ABS, but I did it, and they are holding fine.

I think that so long as you aren't going to monkey around with your panels once they are in the tank, silicone will form a decent enough bond, and if used like a spackle on the back of the panel, will prevent the area of dead space everyone is worried about.