DIY rock? im confused?

ok i read the DIY rock thing on the DIY page. i have a few questions though:

how long till its safe for a fish?

does it really take 4 months till its safe for fish?

how long does it take to get hard?

is it really worth it to make the rock instead of buying it?

im just a tad bit confused and had some questions.

 

HTH I origanaly was going this road but decided to buy all dry rock and cure and seed it myself which is approximatly half the time it takes for DIY rocks

 

I haven't read the DIY threads on 3reef for base rock but can tell you that it's safe to use Portland type II cement. Also if you want to save some $$ use crushed oyster shell sold at any farm supply store and sometimes Menards/HD/Lowes. It gives a nicer texture to the rock than aragonite sand imo and is about $9 for a 50# bag.
Once your rock is made put it in a tub of freshwater let it begin to leach out. Test for pH and change all of the water every day. You should see a rise in pH and then a drop off. It shouldn't take more than 6 weeks before it's usable.

 

ok. could i use tap water or is this unadvisable?

 

Yes use tapwater until you don't see a change in ph. Then put it in RO water for a couple of days.

 

ok. can i use my saltwater test kit to test for the ph in a freshwater tub?

 

I own a concrete company. We mix and haul ready mix concrete to job sites.

What type of rocks do you want? I can probably help you with the mix.

Portland type II cement will take about a month to stop leeching pH exponentially... aka at the extent to which it is safe to put into aquarium. It takes approximately 120 days to become completely hydrolyzed (the process of pulling hydrogen atoms from the surroundings- which causes the pH to rise).
There is a type of cement that is completely hydrolyzed (cured) in about 4 days... i forget the name but i do know it is pretty expensive stuff

 

i want portland II cement. its pretty cheap here (8 bucks for 92 lbs) so i can have 92 lbs of rock for 8 bucks. and i have time to do this. summer is when i want to get it up and running ( 10 weeks.) i want to start on this next weekend though. just to get a head start with the rock.

 

yes..that is what I use. I'm not positive but I don't think the regeants in FW and SW pH test kits are different. But yeah I use my API kit.

 

92 lbs of cement will give you a lot more than 92 lbs of rock... first, cement takes on weight when it is being cured. second, you are not adding in the rest of your aggregate (sand, stone, oyster shells) into your final weight