The Ultimate DIY Rocks!

[airinhere]

Oh, almost forgot to mention. Most ph down products list sulphuric acid as the ingredient. I have enjoyed sucess using muriatic acid from a pool supply shop to neutralize any ph spikes. Add 5 ml at a time diluted in a glass of water. Had a spike in ph in one tank. Ph read at 11 started dosing with the acid and after 15 ml ph was down to 8.2. this morning it was up to 9 so I added another 10 ml dose and now the ph is at 8.0. My tests are being done with tetra tests multiple times. Little bit of acid residue will ruin your results so I verify everything at least twice. Anyone else used acid like this before?

 

[Rhodophyta]

<a href=showthread.php?s=&postid=9151100#post9151100 target=_blank>Originally posted</a> by airinhere
Oh, almost forgot to mention. Most ph down products list sulphuric acid as the ingredient. I have enjoyed sucess using muriatic acid from a pool supply shop to neutralize any ph spikes. Add 5 ml at a time diluted in a glass of water. Had a spike in ph in one tank. Ph read at 11 started dosing with the acid and after 15 ml ph was down to 8.2. this morning it was up to 9 so I added another 10 ml dose and now the ph is at 8.0. My tests are being done with tetra tests multiple times. Little bit of acid residue will ruin your results so I verify everything at least twice. Anyone else used acid like this before?

Muriatic acid is a technical grade of 30% strength hydrochloric acid. That means it is not as strong as the better grade and also has impurities in it that give it a yellow color.

You may not want to bring the rocks you treated inside your house after you read this.

http://www.newton.dep.anl.gov/askasci/chem03/chem03286.htm

It seems the acid can persist and destroy stainless steel which could work havoc on some of the aquarium equipment you might have. Or as in the link, all the kitchen appliances!

 

[Rhodophyta]

<a href=showthread.php?s=&postid=9151100#post9151100 target=_blank>Originally posted</a> by airinhere
.... Add 5 ml at a time diluted in a glass of water....

Another link:
http://antoine.frostburg.edu/chem/senese/101/safety/faq/always-add-acid.shtml

It can be very hazardous to mix water and acid unless you know exactly how to do it properly.

 

[airinhere]

I couldnt agree more. This is something that nobody should undertake without serious caution. This stuff is dangerous if mishandled.

Kids do not try this at home!

That being said, I refer to the wikipedia listing for muriatic acid:

[edit] pH Control and neutralization
A very common application of hydrochloric acid is to regulate the basicity (pH) of solutions.

OH− + HCl ¨ H2O + Cl−
In industry demanding purity (food, pharmaceutical, drinking water), high-quality hydrochloric acid is used to control the pH of process water streams. In less-demanding industry, technical-quality hydrochloric acid suffices for neutralizing waste streams and swimming pool treatment.

[edit] Physiology and pathology
Hydrochloric acid constitutes the majority of gastric acid, the human digestive fluid.

I believe this should be safe to use for marine aquaria. I will post if I am wrong. My goal is that SPS eventually flourish in this tank.

I should also note that the water currently in use in both tanks is for cycling purposes only. I have a 5 stage RO unit that I am using to mix Red Sea Coral Pro salt for the long-term water for both tanks. 240 gallons worth total! I just have to wait out any water incosistencies before making the water change.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9134923#post9134923 target=_blank>Originally posted</a> by gman107
thank you for the response Insane reefer... i really do appreciate it.

No problem Gman That is what this thread is for. I hope you get your rock kured out.


Other thoughts on kuring...
Another thing to keep in mind is water volume vs kuring. I've noticed shorter cure times in large capacity bins. Just filling to the top of the rock doesn't do a lot of good - you can test your water 2 hours later and have it off the charts, so basically your rock is stewing in it's own juices.

Now granted, I am trying to turn this into a spare time job, and so I am spending a bit more on stuff, but I'm getting 2, 55g plastic barrels at a local salvage reseller ($10 each). These have never been used, and are HDPE, clear plastic. Drill them and add a plastic faucet at the bottom. Get a "y" diverter and split the garden hose so I can fill both barrels at once, and leave it to dribble, and open the bottom faucets a touch for flow through - could even run the lines to garden beds, where the rich water would do most stuff pretty good. I will post how that works, and if a 10-20g a day change rate is good, or what. Suggestions are welcome.

I also think that the estimate for kure times has been shortened to an unreasonable amount of time somewhere along the way. IF you can cure in an open waterway (creek, river, pond, ocean, etc), then a estimated kure time of 6-8 weeks could be expected, and is often reported. However, most folks are kuring in closed containers, trying to use as little h2O as possible, and I think that one should expect a lot longer kure - something in the order of 4 months.

That's why toilet kuring rocks Constant water changes mean the rock never stews. Now to convince DH to put a 50g kuring tank over the toilet...

That's my 2 cents, for what it's worth

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9151100#post9151100 target=_blank>Originally posted</a> by airinhere
...Anyone else used acid like this before?

A lot of people do. Most commonly in large freshwater ornamental ponds (using pumps and stuff like ours), or freshwater tanks. Marine tanks typically use a buffer that is other than acid, but I know an old boy here who uses basic chemicals from the drugstore for his 18 year old reef - I know he uses acid to regulate pH when needed...

I think if you soaked the rocks in the acid, you could be heading toward a problem, but you're talking ML into Gallons - not like you are pouring cups of it in or anything. I acid wash/scrub my rock at one point after the rock has been kuring for a week or so, and haven't seen any problems yet.

But you might want to look into a medical grade acid for peace of mind.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9136078#post9136078 target=_blank>Originally posted</a> by KyleP
I too was wondering about the chemical composition. I looked at the MSDS for the Portland and the Quickcure, and from my untrained eye, did not see much difference. I figure you could probably trim off any fiber sticking out from the rock....

This thread will answer a lot of questions you might have on these "other" types of cements:
http://reefcentral.com/forums/showthread.php?s=&threadid=993625&perpage=25&pagenumber=1

ANd I believe a torch is recommended for burning the fibers - leaves a tiny nub that the coralines supposedly like, without the shaggy look.

 

[airinhere]

Thanks for the input Insane Reefer. I was pretty sure the acid was acceptable as I was using it, but would hate to find out someone else had a horror story to share. Like you, I plan to turn this into a side job. I have a big ol pond in my backyard and four weeks seems to be the required time. I just got anxious and pulled one unit early. Experience gained. I have heard that you can use murriatic acid to greatly speed the cure time. Like down to a week or less, but I worry about the strength of the rock afterwards and of course the horrible fumes. Even diluted the stuff is nasty.

 

[tankslave]

<a href=showthread.php?s=&postid=9134135#post9134135 target=_blank>Originally posted</a> by Insane Reefer
No, actually, you can't. I does appear at first to lower the pH, but it has been found that all it does is mask the true reading for a while - then the pH spikes again.

Um "...masks the pH" how does that work??

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9156537#post9156537 target=_blank>Originally posted</a> by tankslave
Um "...masks the pH" how does that work??

Well, I'm not a chemist, but will explain as best I can. As our rocks kure (and cure), they produce heavy amounts of calcium oxide and calcium hydroxide. Also known as KW. The vinegar or acid soaks into the rock, neutralizing the cement that hasn't undergone the transformation to calcium oxide and calcium hydroxide. However, as explained several times, cement doesn't stop curing just because it is "dry". This process can continue for years and even decades, so while you have "neutralized" the cement for a while, the processes are continuing and will shortly overcome the neutralization...

I'm sure someone with more science under their can explain it better, or if you really want to know, you could google or wiki it...

 

[duhfactor]

Has anyone tried using an air entrained chemical mixture with the concrete to make the rocks? I realize that most use rock salt to create voids, but according to a good friend who specializes in concrete addatives and chemistry, rock salt will never work consistently due to it's chemical effect on the concrete. I can't explain it because I barely understood it when he explained it to me. But, he did recommend trying an "admixture" known to "entrain air" into the concrete mixture to make the microscopic voids we are looking for. They will be very small, but many he claims. I guess you use the chemical in place of water to mix up your batch.

D

 

[Rhodophyta]

<a href=showthread.php?s=&postid=9158822#post9158822 target=_blank>Originally posted</a> by duhfactor
Has anyone tried using an air entrained chemical mixture with the concrete to make the rocks? I realize that most use rock salt to create voids, but according to a good friend who specializes in concrete addatives and chemistry, rock salt will never work consistently due to it's chemical effect on the concrete. I can't explain it because I barely understood it when he explained it to me. But, he did recommend trying an "admixture" known to "entrain air" into the concrete mixture to make the microscopic voids we are looking for. They will be very small, but many he claims. I guess you use the chemical in place of water to mix up your batch.

D

You still add water but the admixture creates"suds" that you mix (entrain) into the concrete.

 

[tankslave]

I still dont get what the big deal with pH is. We add CaOH to raise the pH of our tanks anyway. I doubt adding a few cement rocks will have much of an effect. A good system is usually pretty well buffered to begin with. I drip kalk which has a pH of 12, and it barely raises the pH half a point...

 

[Noise]

Where do I get said admixture? Also is there anyway to get my grey portland to turn white? Maybe I should try adding a color to my cement, I am not too thrilled with the grey, but will have to see when it actually gets into a tank.


Also anyone have any more pics of rocks? I want some more ideas for shapes.

 

[Noise]

Now that I think of it, it would be cool to try using the admixture with rock salt to get a variety of different sized pores in the rock. Perhaps that will help water get to the salt inside the rock to help dissolve it.

 

[duhfactor]

My friend gave me a web address for the admixture, but I evidently lost it, I'll call him and get the address and post it today if I can. He tells me it is much more stable and doesn't crumble apart like rock salt. I'll get back with you soon.

D

 

[speckled trout]

Salt, unless I'm wrong, acts as a catalyst to speed up the chemical reaction that occurs in cement as it hardens.

If this is true, and I think it is, then it would weaken the resulting structure. Just as with plaster, a quicker reaction can be accomplished by adding salt. However, the resulting plaster object or mold's strength will be compromised.

I only bring this up because many of you guys have complained that your rocks were crumbling or collapsing because they were brittle. I believe that the addition of rock salt is the culprit.

Personally, I don't add any to my rocks and have never had a problem with their strength or curing time. They also look very real and can be as porous as I want without the addition of rock salt. It's all about technique when constructing your rock to achieve the desired shape or porosity.

 

[Noise]

I haven't had a problem with strength yet. But I am only a couple of weeks into this.

Nice pics, did you make those pieces with a mold or just kinda "plopped" them together?

 

[speckled trout]

And I hope you don't, but this thread is full of comments about individuals whose rocks are brittle.

I'm just trying to suggest a possible reason for this apparent weakness.

 

[Noise]

Well I am doing this for fun anyway, not for need. I am going to try a batch without salt, probably today. Looking to make some branching rock.