DIY Rock (Aragocrete)

[ca1ore]

Am considering making an aragocrete 'shell' to cover one of the corner overflows in my new 265 tank, and am unsure of the current 'best-practice' in using this stuff. Seems that it is:

1. 1 part white (low alk, if u can find it) Portland #3 cement
2. 5 parts aragonite/sand/crushed coral
3. 1 part rock salt (optional)

Mix cement first to ensure maximum limestone activation to reduce cure time. Add sand to a damp, crumbly structure. Mold mixture over form. Cover with damp towel and let set for 2 days. Soak for a while until pH settles.

Do I have that right?

My question is, is the pH-settling/curing time a function of the thickness of the rock structure? If thinner, will it cure faster?

Also, I see some people soak the rock in white vinegar, but is this done prior to the long soaking or right before the rock goes into your display?

Thanks!

 

[fletch999]

I will pm you

 

[Minotauro]

I have the same questions about quantities... I've been reading a lot, but can't come to a conclusion... This seems to be one of the latest threads.

 

[karimwassef]

I experimented with quantities and ratios. your formula has very little cement.

I use 1 part cement, 1 part crushed oyster (washed), 1 part sand, 1 part pumice (washed). The pumice is to be light.

I mix the dry ingredients first... dry cement being last.

Add water slowly until you get a consistency of grits (sticky, not smooth).

after you apply it, sprinkle with lots of aragonite sand.

 

[karimwassef]

salt reduces the cured bonding strength of cement based on my experience and other posters.

if you need some cavities, I would use the salt at the surface before the sand.

 

[uncleof6]

Best recipe is the original recipe, put together by the inventors of "diy rock":

5 parts seaflor special grade aragonite.
1 part White Portland Cement, low alkalinity type (riverside brand recommended)
1 part acrylic shavings.

Rock salt serves no useful purpose at all other than to weaken the structure. It does NOT make the rock porous. When mixed properly (oatmeal consistancy) with the proper ratios of ingredients, the rock is naturally porous, but such is of little consequence as even these pores serve no useful purpose. Oyster shell is another alkalai ingredient (that also contains nitrates and phospates) that really should not be included, and serves no purpose. Oyster shell, in the aquarium hobby, is useful for creating an alkaline environment for African Cichlids. Other than that its only use is for chicken feed. It is intended as a replacement for aragonite in the mix, for monetary savings...it is not a very good replacement.

 

[karimwassef]

Uncle. Please provide your source data or references.

Do you have empirical data showing washed oyster shell leaching?

FYI - Grits has the same consistency as oatmeal.

 

[uncleof6]

Answering a challange, with challange—without offering sources, data and emperical evidence that contradict the challange, is bad form. My sources are the folks that invented the concept of diy rock, and 35 years of experience and research. Just sayin...and yes, I have used oyster shell as a substrate for high alkalinity systems for African Cichlids...

Oatmeal has a much thicker consistancy than grits, unless you prefer runny oatmeal...

 

[karimwassef]

should be easy to cite references and data then
sometimes repeating a strongly held belief makes it sound like a fact. data just is.

I wasn't being sarcastic or flippant - I am running my own tests (mostly because of my white pumice, not the oyster shells), so I would love to see the data.

and - the grits I referenced are thick (not smooth)... but everyone's entitled to whatever tastes and colors they prefer.

 

[Rognin]

I've made my own using Uncles recipe (sort of).

-1.25 part white Portland type 1
-2 parts Oolite aragonite sand
-2 parts Oolite Aragonite pebbels (1-4mm)
-Some dry marco rocks.
-Eggcrate to help structure and self standing.

Looks like this.

It's currently curing in coolers for the better part of a month before I start up my tank.