Making Reef Rocks..

[timberwollf]

Well guys i finally got sick of looking at them prices for Live rock and have been reading up on making my own reef rock i can always wait for it to cure i have enough in my tanks so im not needing any .. So i went out and bought 100lbs of Portland Cement, 100 lbs of Sand, the good kind not the garbage. and about 150lbs of crushed Coral.. Now i need the time and some Imagination i have some idea's on what im going to make.. I will keep you guys updated with Pictures..

 

[thincat]

Well guys i finally got sick of looking at them prices for Live rock and have been reading up on making my own reef rock i can always wait for it to cure i have enough in my tanks so im not needing any .. So i went out and bought 100lbs of Portland Cement, 100 lbs of Sand, the good kind not the garbage. and about 150lbs of crushed Coral.. Now i need the time and some Imagination i have some idea's on what im going to make.. I will keep you guys updated with Pictures..

I made some reef rocks about 6 months ago. I'm still waiting for the PH to come down. The first batch I made was made to thick. I also changed from crushed coral to Oyster shells. That made the rock very porous and a lot lighter. Still waiting for the PH to come down.

 

[timberwollf]

I was doing some reading on how to drop the PH , is by Adding a Air stone in your water Bin it suppose to help it cycle faster, and water changes of coarse.

 

[mmn_usn]

following along to see how it works

 

[Myteemouse]

I'm gonna make some this week end also!
I got a friend that has a 1 foot deep stream in his yard so I'm gonna put all my rocks in there for a few months for constant water changes for better results for stable PH!

 

[timberwollf]

That sounds like a great plan, moving water , no water changes sounds like you have the perfect area to do it , me well its snowing here and the ponds and creeks are now starting to freeze up so i dont have that option wish i did tho , Let me know how it works Mouse..

 

[trido]

Whatever you do! Dont use $100 pounds of cement. Your not building a brick wall or concrete patio. YOu only need it to hold its shape. 40Lbs should be fine.

If I remember correctly. When I used to mix mortar for the brick layers. Oh so long ago....
The ratio was 1 part cement-1/2 part lime-3 parts sand. You surely dont want it that strong.

I made some up last year with a 1/3 cement-3 sand ratio and it is plenty strong. Another trick is to put rock salt into the mix at the last second. Then when your curing, it disolves and makes your rockwork even more porous.

 

[poakley723]

I also have a post in advanced topics. There are few good links in the post.

 

[dnjan]

I have used PVC pipe, heated and bent, to make supports for applying the concrete mixture to. On one of them, I sliced the end couple of inches longitudinally, and then bent those sections out to make "fingers" which I proceded to cover. Makes a nice base for a cup-shaped coral

 

[thincat]

Good plan... I put some in the tank of my toilet. Water change every time you flush, do it when the wife's away................

 

[mmn_usn]

not sure that would be good... lots of Chlorine in the toilet water. I have a stream. I may do this... How long do you leave it in the water?

dnjan- do you have pictures?

 

[thincat]

I air dried it for ~a month then put a few pieces in the tank. I also have most of them in a container and change the water every other day or so. PH was 8.9 and above. It's down to ~8.6 now. Real slow. Can't rush it or I could lose all due to PH shock.

 

[dnjan]

not sure that would be good... lots of Chlorine in the toilet water. I have a stream. I may do this... How long do you leave it in the water?

dnjan- do you have pictures?

Sorry, no pictures handy. I'll see if I get a chance to take a couple.

As far as chlorine in the toilet water - no worse than in drinking water unless you are using some kind of sanitizer/froo-froo thing in the tank. And the amount of clorine absorbed by concrete from drinking water would be negligable. Personally, I would be more worried about polution in a stream.

 

[dnjan]

I air dried it for ~a month then put a few pieces in the tank. I also have most of them in a container and change the water every other day or so. PH was 8.9 and above. It's down to ~8.6 now. Real slow. Can't rush it or I could lose all due to PH shock.

If the pH you are measuring is in the fresh water, I would ignore it. Fresh water has practically no buffering capacity. If you really are afraid that you are still leaching too much calcium from your concrete, put a piece in a bucket of saltwater. Measure the pH before and after, and you will see almost no change. The buffering capacity of saltwater will readily adjust for the small amount of calcium coming out of the concrete. Freshwater, however, will be quite sensitive (pH-wise) to a very small amount of calcium hydroxide.

 

[mmn_usn]

ok. So on average, what is the time needed in the alternate water source to ensure the pH in your tank will not be affected?

 

[dnjan]

I have cured mine in regularly-changed freshwater for a month before putting in the tank. But this was more to protect the concrete from saltwater damage than to protect the tank from pH.

There really isn't that much free calcium inside of concrete that has been cured for a month. Most of it has been consumed in the cement reaction.

 

[timberwollf]

Well if your doing saltwater changes you do it til the ph is normal 8.2-8.3 but why waste all that salt your doing water changes everyday to every other day suggested time is 90 days yes you have to be patient very very patient. if you add before that you will kill things in your tank .. So with fresh water i heard a little secret if you have a tub put a Air stone in it with moving water, suppose to help speed up the curing, Now mind you this is from all the reseach ive been doing i start my own rock building this weekend...

 

[thincat]

Big drop this morning on the PH=7.9...Thanks Don, I did not know that (about freshwater). Will measure it tomorrow in saltwater.

 

[morgan]

so what is the best mix ratio and what does everyone think about adding salt to the mix

 

[thincat]

I mix standard 3-2-1 mix. 3 sand 2 rock and 1 cement. The salt is a great idea because as it disolves it leaves lots of gaps for Nitrifying bacteria due to increase water flow throughout the rock.