The Ultimate DIY Rocks!
- Thread starter JohnL
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salty joe
Active member
I made my rock from three parts fine play sand and 1 part regular Portland cement. I made big sorta flat pieces to mimic a volcanic wall that inspired me while diving in Maui. It is smooth and dense. I kept it damp for a week or so for strength then let it dry completely. When I put in tap water, the PH spiked-no surprise there. I added enough muriatic acid to bring the PH down to 8 and let it soak. Over a month ago, I re filled with tapwater and the PH stayed at about 8. IDK for sure but I suspect letting the rock dry completely is why I don't have elevated PH.
Chasmodes
Well-known member
Mines been dry for 3 weeks, haven't started soaking yet. I will start this weekend with the water changes. They are the base rock for my oyster reef (the oyster cultches or clusters are removable). Here is a pic.
The base rock supporting the oysters:
After the pH comes down and the base rock is ready for the tank, then I'll attach more oysters around the base to fill in the gaps. The remainder of the rock will be hidden by the sand bed for the most part.
The base from underneath:
The rock is pretty dense because I didn't use salt. I'll take the PH in a couple days, and then again in a couple weeks, and come back with provide updates.
CStrickland
New member
Great thread guys and very informative! Thanks to all those who have contributed.
Will this cement be ok? There is no ingredients on the packet anywhere.
Thanks!
See on the bottom where it says "cem 1"?
This is another way to say "type I"
I was able to find type II at my local big box store and avoid a ph spike. It wasn't hard to find or expensive and I'm really glad I used it. Cause it was ready in 72 hours. I don't see any reason that wouldn't work, but I'd find type II, or I/II, if you can.
CStrickland
New member
I didn't realize you were in HK, the ratings outside us and Europe are a little diff, so you might want to do a bit of research. Iirc, you have a lot more ratings within cem2, like 2a, 2b etc. so your cem 1 is the same as our type I, but you have many choices within the cem 2 grade for each of the additives that make it less prone to alkalize the water, where we only have "type II" Idk whether all of those choices would be reef safe like our "type II" is because our ratings don't list which additive they use, just type II. I was thinking if they sold it here it must conform to our "type" rating even though the bag didn't say so. Silly American mistake to think everyone is posting from the states
Another choice would be to try to source a U.S. brand. Here's a pic like what I used, except mine said "type I / II" on the bag instead of II/V. This kind would work too, anything with a II or a V in it is fine.
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shaggss
Active member
I didn't realize you were in HK, the ratings outside us and Europe are a little diff, so you might want to do a bit of research. Iirc, you have a lot more ratings within cem2, like 2a, 2b etc. so your cem 1 is the same as our type I, but you have many choices within the cem 2 grade for each of the additives that make it less prone to alkalize the water, where we only have "type II" Idk whether all of those choices would be reef safe like our "type II" is because our ratings don't list which additive they use, just type II. I was thinking if they sold it here it must conform to our "type" rating even though the bag didn't say so. Silly American mistake to think everyone is posting from the states
Another choice would be to try to source a U.S. brand. Here's a pic like what I used, except mine said "type I / II" on the bag instead of II/V. This kind would work too, anything with a II or a V in it is fine.
Yes there times where I would love to live in the States and have all these wonderful things and on line shopping!
Thanks again for your help. I did ring a company and asked about Portland Cement type II. They said it was available but like so many things, it could have got lost in translat. I'll take a walk down Mong Kok and see what's avail.
Thanks again!
MariusMarinus
New member
Hi Guys,
I have spent the last few days reading through most of these absolutely brilliant and helpful post in these threads.
Planning to do this myself now.
Just generally, after the rock is dry cured for say three weeks could one theoretically cure it directly in saltwater?
Thinking of just hanging it from a local pier so its constantly in the water. It would also perfectly seed the rock wouldnt it? In my opinion its a no brainer but I havent read anything about this? pH of seawater here is around 8.0 so the curing would probably take much longer than very acidic RO water?
Any advice highly appreciated
Thanks
www.irishrockpoolaquarium.com
I have spent the last few days reading through most of these absolutely brilliant and helpful post in these threads.
Planning to do this myself now.
Just generally, after the rock is dry cured for say three weeks could one theoretically cure it directly in saltwater?
Thinking of just hanging it from a local pier so its constantly in the water. It would also perfectly seed the rock wouldnt it? In my opinion its a no brainer but I havent read anything about this? pH of seawater here is around 8.0 so the curing would probably take much longer than very acidic RO water?
Any advice highly appreciated
Thanks
www.irishrockpoolaquarium.com
karimwassef
Active member
If I had access to the sea, I would absolutely have done that.
A few concerns: Theft... Loss in case of a bad storm... Bad hitchhikers.... But acceptable risks.
A few concerns: Theft... Loss in case of a bad storm... Bad hitchhikers.... But acceptable risks.
MariusMarinus
New member
Would you all think it would take longer or shorter or same as curing it in RO or fresh water?
I agree with the risks, could put it in tidepools, kind of protected from stroms where no one goes ;-) bad hitchhikers are still a risk though but worth taking as there will be tons of good hitchhikers ;-)
I agree with the risks, could put it in tidepools, kind of protected from stroms where no one goes ;-) bad hitchhikers are still a risk though but worth taking as there will be tons of good hitchhikers ;-)
karimwassef
Active member
I don't like the idea of low pH curing anyway. I think it deteriorates the strength of the concrete's surface.
I think it's the best option. I would create test blocks that I could take out every week and test in a controlled environment to measure the curing process.
I think it's the best option. I would create test blocks that I could take out every week and test in a controlled environment to measure the curing process.
MariusMarinus
New member
European/non US substitute for Portland cement
European/non US substitute for Portland cement
Very interesting thanks! Will consider that. Starting hopefully this week with some trials that I can use to monitor this method of curing.
I know many have difficulties in sourcing the bespoke portland type II cement outside the US. I have done some research and the one to be found here in Ireland and generally europe is called CEM II/A-L. It goes under "Low Alkali Portland Limestone Cement".
The Low alkali sounds promising but there is 6-20% limestone in it. The Rest is Portland Clinker. Could any of you US guys confirm that this is the same composition as in your preferred cement? Just not sure about the Limestone part...
Thanks and sorry if this was already discussed ( might have forgotten some stuff going through the thousands of posts...;-)
European/non US substitute for Portland cement
Very interesting thanks! Will consider that. Starting hopefully this week with some trials that I can use to monitor this method of curing.
I know many have difficulties in sourcing the bespoke portland type II cement outside the US. I have done some research and the one to be found here in Ireland and generally europe is called CEM II/A-L. It goes under "Low Alkali Portland Limestone Cement".
The Low alkali sounds promising but there is 6-20% limestone in it. The Rest is Portland Clinker. Could any of you US guys confirm that this is the same composition as in your preferred cement? Just not sure about the Limestone part...
Thanks and sorry if this was already discussed ( might have forgotten some stuff going through the thousands of posts...;-)
MariusMarinus
New member
Sorry for you man, that sucks. No problem here in Ireland.
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MariusMarinus
New member
sorry very off topic but if you want a heads up on native marine life here checkout my blog...
www.irishrockpoolaquarium.com
MariusMarinus
New member
When exactly to release/dissolve the salt
When exactly to release/dissolve the salt
I have been doing a lot more reading and actually pored my first few rocks last night.
Again big thanks to INSANE and everybody to share the info here.
One thing I cant seem to find is when exactly to release the salt.
From my understanding in a nutshell you pour the rock let in dry/moist CURE for around 3 weeks and THEN release the salt and after start the KURE?
Or do you release the salt before the CURE a few days after pouring?
Thanks for clearing that up
When exactly to release/dissolve the salt
I have been doing a lot more reading and actually pored my first few rocks last night.
Again big thanks to INSANE and everybody to share the info here.
One thing I cant seem to find is when exactly to release the salt.
From my understanding in a nutshell you pour the rock let in dry/moist CURE for around 3 weeks and THEN release the salt and after start the KURE?
Or do you release the salt before the CURE a few days after pouring?
Thanks for clearing that up
Mael
New member
going to run the first PH test on my first batch fo rock tonight. Based on alocal club meeting about DIY rock I did 2:1 ratio aragonite sand(coarse) to grey portland. Made about 20 frag domes and 10 frag "discs" out of the mix, let dry for a week then put in back of toilet for 4.5 weeks which gave it 3-5times daily water change since it was in the guest bathroom. Then went into buckets with water change water for 2 weeks and was changed out 3 times during the 2 weeks. Will post results tonight sometime but I am hoping with the insane amount of water changes it went through the first 4 weeks it should be good now.
Im only going to use a few of them in the DT and the rest will be for growing out frags into mini colonies in the prop tank.
will get pics and PH results later tonight hopefully.
Im only going to use a few of them in the DT and the rest will be for growing out frags into mini colonies in the prop tank.
will get pics and PH results later tonight hopefully.
CStrickland
New member
The toilet method is very cool, I woulda done that if I couldn't source the neutral PH Portland. When I was looking into it I was curious about exposure to stuff in tap water, like copper or phosphate and stuff. Not curious enough to actually look it up, lol. Did you do anything to account for that?
