cement for DIY rocks
 

headaches...

Ive read through a bit of the literature online about making DIY rocks out of sand cement and rock salt, but what kind of cement should i be using? I know types I through III are fine, but that's American labelling. Canadians use types GU through HS... anyone know what type "I" is in Canadian?

oh and hardware stores don't stock rock salt after winter. if anyone has some that i can snag let me know :)

we used portland cement 10 or 20 , crushed oyster shells,sand, water

^ Yep, Portland 10 or 20. Try feed stores for the oyster shell, and rock salt. :)

I have 30 bags of rock salt, but its here in Victoria.

use type 10 cement. Water softner salt is better anyhow, its cleaner. Also always available. :biggrin:

The mix I used was 1 part cement to 3 parts "other" other being salt, sand OS ect. With mine I used 2 parts salt, 1 part Caribsea seaflor special grade sand (cause I had some). And 1 part type 10 cement.

I just put my first piece in my sump about 2 weeks ago and today I noticed a few spots of coraline on it. :smile:

Water softener salt would work too, and is around all year :)

I've got a couple bags of water softener pellets. Let me know if you want them.

As for the cement, I looked all around town for the low alk cement but no one carries any, so just normal type 10 from homedepot works.

I picked up some quick setting cement, sets in 20 mins. Hopefully it will work okay.

The quick setting has an additive in it to make it set quick (pretty sure)...not sure if that would harm the critters or not...?

I've been told post haste concrete isn't as strong as regular portland cement.

Checking in one of the books here at work, Target (brand) says ... "Where superior salt resistance or strength characteristics are required, consult target
products for advice on appropriate products" when it comes to post haste

I forget which one it is, but its either calcium or lime that is added to make it cure faster

Good old calcium chloride, the stuff you add to your tank to raise calcium, is added to cement to make it cure faster.

Rona carries the white cement I used to make my rocks. If your ever out in the Walnut Grove area you can have the rest of the bag that's taking up space in my garage. I'm never going to use it.

Rob

there is another thread on this topic and IMO the rock made with softning salt looks way better. dont bother with the rock salt.

The other thing I considered making some rock out of ... was colored, sanded grout .. It comes in almost any color you want .. so why not have purple base rock? :) Though I imagine they would have to be 'ph cured' for a long time

cool thanks guys. always dependable. Ill go buy some type 10 tomorrow and get down to makin the rocks on tuesday (or the next sunny day). thanks for the offer spoot, but i think ill just buy the water softener salt when i go get the cement.

I am goign to be making up a batch of DIY rocks soon and I am wondering why Oyster Shells? Is it just for the texture or does it help by adding calciuim?

By the way Buckerfields right off #1 Hwy in Abbotsford has crushed oyster shells in Bulk.

This is a piece of homemade rock, that Mike did a few years ago. Cant tell it form the other now, except for the different look from its materials. Its supporting a main portion of my reef.

I can take a better pic if you wish. Attachment 2839

Type gu (general use) type 10 portland cement. I build ponds for a living and have had much sucess with this. Doesnt affect fish.
P.S cement takes 28 days to cure DO NOT PUT IN TANK UNCURED when cement cure it releases off gases. Good Luck

Oyster shells are just to add texture. I used aquarium gravel in mine, but I think oyster shells would give a coarser look.

thanks guys. i endeed up getting the specialty white portland type 10 cement. little bit expensive but I think it will blend in better in the tank than gray cement. A small batch has been curing for a week or so now. I think i might crack one open later to see how it went.

How did the aquarium gravel work? I have some kicking around and was considering a DIY batch.
Kevin

It made it a little bumpy, it depends on how much you use. Do some small batches an experiment until you get the look you want.

I have made some test batches and the softening salt thats in the rock will not disolve. I have had one piece soaking for 3 weeks to a month and still when i crack it in half there is undisolved salt. Salt that is 1cm from the outside of the rock and still it doesnt look the slightest bit disolved. Anyone else notice this ?