DIY Live Rocks
- Thread starter hckycoz
- Start date
thegrog
Active Member
lower your ratio of portland cement to shell. I found that a 1:4 ratio (1 cup cement to 4 cups shells) makes a good, porous rock....but a little weaker. A 1:3 ratio is a lot stronger, but not as porous. If you want to get fancy, a 2:7 ratio is the best of both worlds!
Also, let it sit in the mold for it least 3 days to set up nice and firm, else it definately will break apart right away.
Also, let it sit in the mold for it least 3 days to set up nice and firm, else it definately will break apart right away.
jlem
Active Member
I have made a few batches using
2 cups oyster shells
1 cup crushed coral
2 cups type 1/2 portland cement
enough water to make it like cottage cheese
let sit in damp mold for 1 day ( it's 100+ degrees so in winter I would do longer )
soaked it in huge tub of fresh water changed every other day for 6 weeks
soaking it now in saltwater from water changes and I'll check the PH in a few days.
2 cups oyster shells
1 cup crushed coral
2 cups type 1/2 portland cement
enough water to make it like cottage cheese
let sit in damp mold for 1 day ( it's 100+ degrees so in winter I would do longer )
soaked it in huge tub of fresh water changed every other day for 6 weeks
soaking it now in saltwater from water changes and I'll check the PH in a few days.
hckycoz
Member
well i pulled the second batch out today and the outer edges kinda started breaking off. I was very happy with the shape and i cant tell the texture right now(coverd in sand). as i type this i am running water in a bucket to cure them. I will get back on the texture and maybe some pics
shiby1510
Member
yes I know.. and it is not much use in trying the other h/d's either... they just carry the quikrete junk...
your best bet is checking the yellow pages... I was lucky enough to have a place right near me that actually makes concrete.. so i got myself the good stuff after my troubles with quikrete... if you still cannot find any let me know
your best bet is checking the yellow pages... I was lucky enough to have a place right near me that actually makes concrete.. so i got myself the good stuff after my troubles with quikrete... if you still cannot find any let me know
thegrog
Active Member
Originally Posted by shiby1510
i have some bad news for you.. quikrete is no good..
believe me i've been down that road... it will crumble!
Quikrete is a BRAND, portland is a TYPE of mix. If you look at the specs of their portland mix it will be the same as any other portland mix.
The rocks I made with my Quikrete portland mix are holding up fine. Just have to play with the ratios a bit. Made one batch that totally fell apart, one batch was so solid that they are garden rocks now, and the rest are in a growout tank or curing as we speak!
i have some bad news for you.. quikrete is no good..
believe me i've been down that road... it will crumble!
Quikrete is a BRAND, portland is a TYPE of mix. If you look at the specs of their portland mix it will be the same as any other portland mix.
The rocks I made with my Quikrete portland mix are holding up fine. Just have to play with the ratios a bit. Made one batch that totally fell apart, one batch was so solid that they are garden rocks now, and the rest are in a growout tank or curing as we speak!
thegrog
Active Member
Originally Posted by shiby1510
actually quikrete... is not like real cement.. it is already mixed with sand and other stuff.. :yes:
A standard Quikrete bag....yes. You can buy Quikrete Portland cement that does not have sand, rocks, etc in it. If the bag says "Portland Cement" on it, it complies to federal regulations (and ASTM C 150) for ANY portland cement. In other words, does not have any "sand and other stuff" in it. It will be the same as any other brand of portland cement you find.
It is harder to find, but better for rocks is the portland type II mix. The type I will do if that is all you have available. Type II takes longer to cure, but will stand up to a greater range of environments (water, salt, temp, UV, ect)