The Ultimate DIY Rocks!

[impur]

<a href=showthread.php?s=&postid=13687282#post13687282 target=_blank>Originally posted</a> by speckled trout
Mine were made with Alamo's Portland Cement and oystershell. Nothing more and nothing less. My coral have never had a problem with them, either. The pH is a stable 8.3, as well.

Good for you. Thanks for the help.

 

[rfd515]

Impur, unless I missed your post, you may want to describe the process you went through so people could more help you.

It's impossible to guess one of the many factors that could be causing your issues.

 

[impur]

<a href=showthread.php?s=&postid=13688247#post13688247 target=_blank>Originally posted</a> by rfd515
Impur, unless I missed your post, you may want to describe the process you went through so people could more help you.

It's impossible to guess one of the many factors that could be causing your issues.

No problem! I have them posted in this thread, probably several pages or splits back.

Here are my incredients. I do not have an exact ratio, i mixed to get the look i preferred

Mixed to a cottage cheese density

forming the rock in a damp sand mold

Next i put the whole thing in a large plastic bag, sealed it up and let it harden for 28 days.

After hardened, i placed them in a 25gallon rubbermade tub on my back porch and have done weekly waterchanges for over 6 months on these ones, same process for the ones i made 14+ months ago.

 

[rfd515]

I wonder if sealing it in the plastic bag could have affected it

 

[impur]

My first batch i did not use the bag and just let it harden in the mold then into the soaking tub. They have been soaking for about 14m.

I've tried letting them dry in the bag, out of the bag, for 28 days, for 1 week, for 2 weeks, for 3 weeks all before going into the soaking tub. All have the same result. Months and months later pH is still over 10.

 

[Whalehead9]

why is there salt in the sand mold? Salt slows curing, I understand it in the rocks to create crevices, but in the molding sand?

 

[Azazael13]

I use salt in my molding sand to help create impurities in the surface, just like a crevice in the rock.

 

[speckled trout]

Good for you. Thanks for the help.

I wasn't trying to be a jerk. I wasn't trying to be sarcastic, either. You, however, are.

I'm becoming skeptical that using these rocks is even practical?

It seems that your impying that rocks cannot be made that are reef safe. I was trying to show you that this is incorrect. I've been making them for years, without any type of problem. I didn't make them like you did, either, and I stated that in my reply.

 

[speckled trout]

I could be wrong, but you may need more water exchange to get rid of leaching substances. I placed mine in a river for 3 months. This allowed it to leach any harmful pH raising substances that the cement may have contained.

I then measured the pH of water in which they had been allowed to soak for another week to insure that I got a good reading. THe water had a pH of 8.3. By the way, I tested it in SW.

 

[impur]

The only addition i have that you didn't use is sand and salt. Neither of which would raise pH, especially after 6 months. The salt has been dissolved and sand is...sand.

You put yours in a river. I put mine in a bucket and changed the water weekly. Pretty similar if you ask me. Unless you have a magic river??? :lol:

 

[impur]

<a href=showthread.php?s=&postid=13694255#post13694255 target=_blank>Originally posted</a> by speckled trout
I could be wrong, but you may need more water exchange to get rid of leaching substances. I placed mine in a river for 3 months. This allowed it to leach any harmful pH raising substances that the cement may have contained.

I then measured the pH of water in which they had been allowed to soak for another week to insure that I got a good reading. THe water had a pH of 8.3. By the way, I tested it in SW.

Yah that could be it. Really thats the only thing that could be significantly different between our methods.

I plan to move my rock inside and place it in some tank water from my next WC. I'll add a powerhead and heater and since i do weekly WCs i can keep up with that on the rock. Its worth a shot, i really want to use my rock!

 

[speckled trout]

Utilizing a river increases the water exchange millions of times over a tub. There isn't any comparision between our methods.

I wasn't in a hurry to extract the rocks, and let them soak for 3 months.

The most important thing I've learned in this hobby is that nothing good comes quickly.

Also, what type of cement did you use?

 

[impur]

Well i'm not putting mine in the river. There is a sewage plant upriver.

I used Lehigh white Portland Cement

 

[Inukshuk]

Hello impur,

Why don't you do a quick test?
You may want to sacrifice one of your rocks (pick the ugliest) and put in your dirty river for a day or two (but no more). Then test the pH... if the pH went down then your rock just needs more water changes.

If the pH of the sacrificial rock is still high, then there is something fishy. If so, check for fishy ingredients: Mix one more small batch, but this time DO NOT include any cement. Then submerse the mix in water and test pH.

The cement is the only ingredient that should contribute to the increase in pH. So if you still have a high pH even without the cement, then you got some weird sand or salt with basic pH.

I hope this helps.

 

[Rhodophyta]

<a href=showthread.php?s=&postid=13694816#post13694816 target=_blank>Originally posted</a> by impur
Well i'm not putting mine in the river. There is a sewage plant upriver....

Just think how nasty that water would be if there were NO sewage plant upriver.

 

[Rhodophyta]

<a href=showthread.php?s=&postid=13689792#post13689792 target=_blank>Originally posted</a> by rfd515
I wonder if sealing it in the plastic bag could have affected it

Cement needs both oxygen and humidity to cure. so sealing it could slow the process.

 

[impur]

I'll give it a shot!

Rhodophyta - i tried it both in the bag and without. Same results.

 

[speckled trout]

Lehigh white Portland Cement

This could be your problem. Has anyone else used this brand with success? I used Alamo's Portland Cement. They might have different ingredients.

 

[Insane Reefer]

It is what I've been using for Years.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=13700086#post13700086 target=_blank>Originally posted</a> by speckled trout
Has anyone else used this brand with success? (Lehigh White Portland Cement)

I use this brand and type exclusively, and have for years. Nothing wrong with the cement.