The Ultimate DIY Rocks!

[michaelalan]

Insane,

I have a new test for your lab monkeys and a suggestion for a “control” rock.

Baking at a lower temp.

When slow cooking a roast, it is suggested that the temperature is not to exceed 212 degrees F because that’s the magical evaporation point for water. Therefore temperatures above 211 may inhibit the hydration effect. We should test that theory.
Calcium melts at 1548 degrees F so my theory is that anything over 211 degrees is wasted energy unless you are hitting 1548 degrees.

Control Group â€"œ
In any good experiment there is a control group, a constant to test the “new method” against. Out of every batch of rocks mark one rock as the control and do the normal water RO water soak. No water changes, no vinegar additives, no nothing. Then when you test the “new method” rock you have the control rock to compare it to.

 

[GuySmilie]

<a href=showthread.php?s=&postid=10073843#post10073843 target=_blank>Originally posted</a> by goldmaniac
<snip>

but one statement of concern, on the side of the bag:

"SLIPSTOP has been applied to this bag"

anyone know about SLIPSTOP? slipstop-d0t-com shows products that are applied to floors to eliminate slipping and falling. but nothing about actual cement additives. anyone know if it's safe for our tanks/ what the product is made of? I'm betting it's added to the portland cement mix, although I'm desperately hoping they mean that "slipstop has been applied to [the outside of] this bag [so that you don't drop the bag]"
I doubt it. Common sense says it's a treatment in the white portland cement.

Any opinions?

- G.

Sound like some type of abrasive additive. Possibly silica as that is listed as well. This is what is used in 'slip-resistant' paints. Call or write them and ask their tech folks specifically what it is. Most of these cement manufacturers have full-time lab folks on staff and are willing to answer your concerns.

 

[goldmaniac]

Thanks, GUY..

I forget, it's Silica that we don't want, right? Silicates are ok?

I'll call them.

- G.

 

[ReeferAl]

Regarding curing of home-made rock, I've heard of people using RO waste water. It seems like a good idea to me as it makes good use of water that otherwise just goes down the drain and it would give a partial water change every time you generate any RO water.
The method would require a tub or barrel (Rubbermaid trash can for example) into which the RO waste would flow. The tub would then have an overflow pipe near the water surface that would flow down the drain. The new water would have to enter near the bottom of the tub which could be accomplished by a stand pipe extending from above the water line to near the bottom of the tub. The waste water would run into this pipe, down to the bottom and then flow back upward over the rocks in the tub. The waste water line need to drip into the pipe and not run all the way to the bottom itself to maintain an "air gap" that prevents back-flow, otherwise it would be a code violation and potentially dangerous should the RO check valve fail.
Next time I make some rocks I plan to use this method.
Allen

 

[aallison]

Hey all
This is my first post at RC, but I just had to say that this is one of the best and most helpful threads I have come across in a long time. You guys are doing some great work here.

Anyhow..

the reason I am posting is I have been thinking about making my own rock for my new 70 which is in the planning stages, and was looking for ways to make lots of thin shelves and fan shapes which seem to be problomatic due to strength issues.

One thing I have been considering but haven't seen anyone post on it yet is the idea of using eggcrate as a skeleton and then packing the crete around it. Think of it as plastic rebar. Of course, you wouldn't be able to bake it so it would take longer to cure, but I think it might make it a lot more structurally sound?

Anyone have any ideas/experience?

Thx, Andy

 

[Azazael13]

Aallison I would give you the Welcome fish, but I can't look for it atm, so instead.

Welcome!

As for egg crate this should work just fine, there are some pictures somewhere around page 25 in the 2nd thread where someone took PVC and Eggcrate to make his rocks.

 

[Insane Reefer]

Ok, first a warm RC welcome to the new posters!
And I personally would like to welcome Mr. Wilson â€"œ I had invited him over a couple of months ago, but had given up hope of his participation…

I would like to point you new folks to this short article â€"œ it will help you understand the basics of cement and help answer questions you might have. Ignore the bits about additives - just read the part that explains cement.
http://www.lmcc.com/news/summer2006/summer2006-06.asp

And now on to some answers.

Mr. Wilson. The answer to your question of what are we trying to accomplish, lowering/stabilizing the pH or leeching the “salts”/lime/C-H, I think is “Both”. They seem to go hand in hand. The pH doesn’t stabilize until the unhydrated materials are flushed out. That is one big bonus with the hydraulic cements you work with â€"œ the added polymers or epoxies seal the materials and once cured, the pH is stable, however I believe you sacrifice a lot of biological potential as fortified cements lack the vast numbers of capillaries and pores of traditional cements.

Michaelalan. Welcome.
I truly doubt that your rock hasn’t kured in the creek because of pH or ALK. If there is any fish or amphibian life in the creek (likely, even for TX), the pH is low enough to kure your rock. I would hazard a guess that your rock is on the dense side, and you threw it in too quickly. Maybe breaking a piece open and looking at the matrix will help ID the problem? ALK, to my knowledge has never been part of the kuring equation â€"œ these rocks will have ALK off the chart, literally. I use “SeaLab” test strips for my Saltwater tank testing, and it tests to 300ppm and that color is sort of a muted dark green â€"œ my ALK on my Bio-cube, the day after I glued in my back-wall was Indigo Blue, and took 3 months to drop to the blue-green range where it currently stands. Rocks produce ALK, ALK isn’t going to be a problem.

And you mentioned a great test â€"œ too bad I had done this very thing this last week and weekend, lol â€"œ sorry. I sat down just now to report my results, so here goes…

I had googled around and found that what I have been experimenting with for “Jiffy Rocks” was called “Steam Curing”, and that two types exist â€"œ Pressured Steam (or Autoclave Curing) and Un-pressured Steam. The un-pressured steam cure is exactly what you describe Michaelalan. My previous bakes were all done on young rock, 24-36 hours old and at high temps of 400-450°F, for a period of 4-6 hours, with moisture provided though-out and the stove vent covered to prevent steam from escaping. The rock came out hard â€"œ as say maybe week old rock or maybe older would be, and after 3-7 days in a varying vinegar solutions all came to an end pH of around 9.0 (at the two week test point).

This last batch I did, I did dramatically different. I used low temps of 225°F for 12 hours, again capping the vent to prevent moisture from escaping. The rock was much more brittle and crumbly â€"œ a marked difference from the high baked pieces. And while that might be attributed to differences in mixes, I have made a LOT of rock over the years â€"œ I have gotten pretty consistent in its manufacture.
As the rock was already cooler than when I normally plunge it, I proceeded directly to the plunge on removal from the oven. When plunged, there was almost no crud in the water, certainly no plumes of purging stuff as evidenced in my other bakes. So after a typical 24 hour salt release, I went another way again, and used pure vinegar to kure these rocks in. I posted pics of that, page before last I think, or in my gallery. I left the rock in until the evidence of a chemical reaction had seemed to have stopped â€"œ no more bubbles something like 5 hours. I rinsed these extra well, and let them soak in a clean bath for a day, then refilled for pH testing. My Tetra Test goes to 10 on the pH, which is a dark purple. At 8 hours in test water I tested for giggles and at 2 drops the water had already darkened to purple â€"œ I didn’t even need to add the rest…
My conclusions are that pure vinegar â€"œ a 5% solution, is much too aggressive to reduce the pH â€"œ it is simply stripping away layers to reveal new “hot” layers, or that is what I am thinking anyway. My next batch will be a 2.5% solution â€"œ slightly stronger than my previous solutions. Will report on that when it is ready.

And I was not impressed with the low bake â€"œ the rock did not seem as sturdy, and it made a complete mess of my stove. Crusty puddles of crud, corroded foil bits â€"œ it is a mess…

So I don’t recommend this method to anyone at home.

Goldman â€"œ you really need to become friends with google, lol.
Read this page (it was the third google result, hehehe) http://www.slipstopusa.com/
I think you found the motherload, lol! Based on what I am reading at this page and site, it sounds like the method is mostly comprised of aggressive acid? washes and then a treatment to seal it. What does it mean for the bag you found? Dunno â€"œ here is the contact page for your manufacturer http://www.federalwhitecement.com/contact.htm
Let us know what they have to say…
And yes, Silica is ok, silicates are bad.

Most of these cement manufacturers have full-time lab folks on staff and are willing to answer your concerns.

Guy â€"œ it would be great if that were the case, but I rarely get my emails returned when contacting anyone in this industry â€"œ including manufacturers. Or maybe I am just asking too many questions, lol.

ReeferAl, this is what I have one of my LFS’s doing and it seems to be working great. He does soak it for a week in used saltwater afterward, but he has the run-off line running to a barrel outside. Had to heat it in the winter though â€"œ he use a stock tank heater.

Aallison â€"œ welcome!
Egg-crate and PVC are helpful for making rock. You need to drill holes in the PVC to allow the cement places to “grip” the slippery surface, and sanding with rough sand-paper will help too. The holes also allow for contraction of the cement as it cures. You can also “bend” PVC outside, using a heating gun, torch or grill, but be careful â€"œ fumes can kill you. Use heavy gauge zip-ties to connect pieces together. Take pictures!

 

[onnenmd]

I just tried the method using a balloon to make a tunnel..........it popped the balloon everytime!!! Anyone have some tips on how to use a balloon without it popping? That was frustrating because I thought it was going to look awesome, but then *pop* :eek2:

 

[onnenmd]

I'm going to try and do the double up methond that insane mentioned...what is the best way to do that and how do you get them doubled up (what do you use to put one in another without ruining it).

Why do you think the water filled makes them stronger? More substance other that air, maybe?

 

[michaelalan]

Thanks Insane, glad to hear you tested the low temp bake.

I guy in my reef club offered to auto clave it, I am thinking of taking him up on his offer.

 

[Insane Reefer]

Make sure not to use water balloons Onn - they bust every time, lol.
Not sure why the water makes them hold up better. I had best results with animal balloons - you can get two pieces out of those too. Doubling can be a pain - I had best luck with 6" round balloons - used the round end of a shrimp fork? thingy and just sort of pushed one inside the other...

Also, don't blow them up all the way - the less air, the stronger the rubber stays.

 

[Insane Reefer]

I think I need another test bake, just to be sure, but I really, honestly think the high bake did better than the low bake.

If you can get him to put your rock in an Autoclave, Michaelalan please, please, email me for the "Lab Monkey Test Form". I really would like to add that data to the data I have for the un-pressured bakes...

 

[mr.wilson]

Thanks for the warm welcome. I remember talking to you in a few related threads, but I guess I never got around to this epic thread. Sometimes I get so many threads going on so many forums, it becomes a full time job.

You are correct about the lack of usable pores in the polymer modified cement mixes. I wouldn't ever use them for rock, just on walls and PVC parts.

I'll post some pics in a couple of days.

 

[mr.wilson]

If you fill the balloons with water, they will resist heating from cement curing and they will not off-gas.

 

[mr.wilson]

<a href=showthread.php?s=&postid=10074209#post10074209 target=_blank>Originally posted</a> by michaelalan
I tired the 30 day river soak and I saw no reduction in Ph. However, the “soil” in my area is limestone rock, so the alk of the creek is already off the charts!

Test the creek ph before you waste 30 days like I did.

Curing the rock in a river will also turn your rock into a phosphate sink, not to mention the bacteria and toxins that will populate it.

If you cure it in a river, you should bleach it to sterilize it, and soak them in acid to remove the phosphates.

 

[aallison]

Hey all and thx for the warm welcome!

For some reason I am having a hard time linking into the earlier split threads....so I am sure I am asking a redundant question...but anyhow..

IR..what is the purpose behind keeping the oven humid when you bake the rock? Your recipe calls for water containers in the stove and keeping them full but I didn't see in a thread why this is so.

Just trying to figure this all out
Andy

Rock on Dudes!

 

[Insane Reefer]

I know where you are coming from Mr. Wilson, lol.
But glad to have you here, now

<a href=showthread.php?s=&postid=10076558#post10076558 target=_blank>Originally posted</a> by mr.wilson
Curing the rock in a river will also turn your rock into a phosphate sink.

We typically recommend kuring in a Clear waterway, never muddy waters. And a run by the car wash for the high pressure sprayer (rinse only!) to blow the rocks out after a water-way kure is in order. Also a few days in the sun to "bake" the rock a bit, but personally I don't think bleach soaks are a good idea - chlorine will be trapped in the cement and can do nasty things - nastier than potential hitchhikers. Usually, anything living in freshwater will die off in saltwater.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=10076599#post10076599 target=_blank>Originally posted</a> by aallison
..what is the purpose behind keeping the oven humid when you bake the rock?

Well, as you read in the article I had just posted for you new folks, cement requires moisture (H2O) to hydrate. If you simply placed the rock in a hot dry oven, the moisture in the rock would quickly be depleted, and no (or very little) hydration will occur - and we then have rubble.
By maintaining a moist environment during the cure, more hydration occurs - and this is true with both my new method, and with the traditional method.

 

[mr.wilson]

Chlorine off-gasses very easily, and a dechlorinator (sodium thiosulphate) bath is also a good idea, but you're right, the fewer poisons the better.

Acid will remove the phosphate as it's a surfactant. If you use enough of it, it will kill the bacteria as well.

 

[Insane Reefer]

The Great ALK Debate

The Great ALK Debate

Ok. It has been theorized and asked several times in this thread - Will MMLR rocks help raise/maintain Calcium or ALK levels in an established aquarium?
Michealalan got me thinking, lol. I realized I have results sitting in front of me - my back-wall. This back-wall weighed almost 7lbs and was installed at the beginning of March (see my gallery). I can't find any batteries, or I'd snap a new pic, but 3 months later, it is growing coralline and I've glued shrooms and polyps to the back-wall and it is starting to fill in nicely. It measured, in a saltwater test bath, at just under 9.0 pH, so I used it.

But the important part.
I have been having a devil of a time keeping my calcium up above 400, never-mind 450, lol. For now I have abandoned the effort as I have nothing that really needs it right now.

My pH and ALK, which I just tested are at 8.0 and "off the chart", respectively. If I had to guesstimate, I'd say ALK is better than 350ppm, and probably closer to 400ppm - and this is about as low as it gets.
I haven't done a water change in 3 weeks *blush*. So this is just as it stands.

ALK is being maintained at high levels. I am only adding Kent Coral-vite at this point - a few drops every few days. Calcium is not being maintained, and has to be replenished.
I think I remember that calcium and alk are sort of mutually exclusive - that when one is high, it is more difficult to maintain high levels with the other. Someone more into reef chemistry might interpret this differently, but I think this is one test result on the "Yes" side of "Can the rocks replace (at least to a point) KALK?"

Thoughts?