Cement rocks

[Cory]

Hey im thinking of making diy portland cement based rocks for an upcoming build, but im worried that even after curing them in fresh water to reduce high ph that it will leech aluminum into the aquariums water. I heard that aluminum is an active i ingredient in portland cement. Would it leach?

 

[ihavecrabs]

I would worry that the rock would disintegrate over time.

For example, when installing a water softener in a home, it back washes the resin with saltwater to regenerate it. On the installation guide, they specifically tell you not to plumb it into the homes plumbing if you are on a septic system. This is because that most tanks are cement and saltwater will corrode cement overtime.

I would think the same issue would exist for cement DIY rocks. That said, I have not done research on this and I know DIY rocks are growing in popularity. I'm sure there are some users our there with firsthand experience that can advise on how they hold up.

If they do disintegrate, no amount of freshwater rinse and soak will get remove the aluminum as new rock will be exposed over time since the cement is dense and not porous like reef rock is.

Hope my rambling helps!

 

[HawaiianReef]

Are pilings that are used for bridges and marina piers/docks made with a different compound of cement?

 

[robbyg]

http://www.tfhmagazine.com/saltwate.../creating-your-own-live-rock-full-article.htm

 

[ihavecrabs]

Some good points above... Like I said above, I'm sure there are quite a few R2R users that have done this and can speak to how they hold up over time and if aluminum is a concern.

 

[Cory]

Im not worried the rock will fall apart because theve been made by many others and not many report it falling apart. Im worried about it leeching aluminum because an ingridient is aluminum.

 

[Randy Holmes-Farley Verified Community Expert]

I don't know if aluminum is a concern. The pH (and alk) is until it is well cured.

 

[Cory]

I don't know if aluminum is a concern. The pH (and alk) is until it is well cured.

Could i make my own cement and not add aluminum? Just calcium hydroxide and silica sand for example?

 

[Randy Holmes-Farley Verified Community Expert]

Could i make my own cement and not add aluminum? Just calcium hydroxide and silica sand for example?

i don’t know cement recipes and what works ok.

 

[lavoisier]

Way back when I made concrete rocks for my aquariums. You can get pretty creative using concrete. They had to be cured in fresh water for about 6 weeks. I never tested for aluminum but my aquariums thrived.

 

[Cory]

Way back when I made concrete rocks for my aquariums. You can get pretty creative using concrete. They had to be cured in fresh water for about 6 weeks. I never tested for aluminum but my aquariums thrived.

Did you use portland cement?

 

[lavoisier]

Yes.

I got really exotic at one point and used pasta to create lots of "holes" in the rock. After six weeks the pasta would have dissolved out! However, the rock was still extremely dense compared to coral rock.

 

[HawaiianReef]

Hey Cory, if you decide to go on with this project, could you do a thread on it. I've been really interested in this process.

 

[Cory]

Hey Cory, if you decide to go on with this project, could you do a thread on it. I've been really interested in this process.

Yes i will. The process is called aragocrete rocks. Lots if threads about it.

 

[HawaiianReef]

I have checked out a few, but lost interest as I couldn't find anyone considering leaching elements.
I like your approach. Addressing these concerns and seeing if they are a concern to begin with.

 

[artreef]

I have made many artificial rocks for my clients. I made sure it is very porous so it cures fast and efficient.;)

 

[Paul B]

I have been making cement rocks for my tank almost from the start and it is running almost 50 years now.
No problems yet.
https://www.reef2reef.com/ams/build-your-own-rock-for-practically-free.180/

 

[RockyroadReef]

I have made many artificial rocks for my clients. I made sure it is very porous so it cures fast and efficient.;)

No leaching problems?

 

[Cory]

I just went and made my own rock sculpute with super glue and oolite sand. Looks awesome. And i dont have to cure it or worry about high ph or aluminum

 

[Randy Holmes-Farley Verified Community Expert]

I just went and made my own rock sculpute with super glue and oolite sand. Looks awesome. And i dont have to cure it or worry about high ph or aluminum

Sounds great.

Got any pictures?