Cement block reefscape.

[MalteserReefer]

Literally my first ever thread, so here goes.
On a reeftherapy podcast from reefbuilders some time back, the late Jake Adams mentioned something about aquascaping rocks being overpriced af, and that you can literally use cinder blocks instead. Is this a thing? I’m planning a 700gal and cement blocks (whole or sawed in half) would make a good base rock. I’ve seen it in a few reef tanks online but it’s not commonplace. I’m only taking it seriously because Jake Adams mentioned it. By cinder blocks I mean cement blocks, where I come from they’re made with local limestone and cement. That’s it.

Cons:
1. Concrete dust… they need to be pressure washed
2. Cement is basic… They need to soak in a bath of water until they stop messing with the pH
3. They ugly

Pros:
1. They’re strong, they’ll never break if you put heavy scaping rock on them
2. They’ll last forever
3. They have holes you can use as shelter if you have large tangs, angels etc
4. They’re cheap as chips
5. They’re very porous
6. You can easily cover them with live rock once the skeleton of the scape is done.

 

[bluemon]

I personally would never.

The calcium carbonate make of the reef rocks does a great job of being a buffer amongst other benefits. And those pros of concrete really also applies to "reef rock"

1. Reef rock is just as strong, maybe stronger as they are not as brittle as cinder blocks. I have literally never heard of rocks breaking because of heaving scaping.

2. Reef rock will last just as long as cement in the scope of life. What do you think is happening in the ocean? Are these rocks just dissolving? These reefs have lasted millennia. It'll last long enough for you to enjoy before we all die

3. Reef rocks have holes as well, and sometimes better suited for fish that like it a bit tight. Open big caves aren't that great for smaller fish

4. That's fair, but you can get some good deals on dry rocks

5. Being too porous can also be a problem. I would argue reef rocks are the best in terms of porousness balance. Proof is in the ocean.

6. I guess if you have a good balance of reef rock and cinder blocks, it should be okay, but I personally am not a fan of too dense of rock work that would effectively hide the cinder blocks / make it so that it would actually play a big part in being a "base", so I really don't see the point. I have a rock/base heavy rockwork right now and I am not the biggest fan

 

[MalteserReefer]

What an in depth reply!
Thanks

 

[Ordovician_Reef]

Literally my first ever thread, so here goes.
On a reeftherapy podcast from reefbuilders some time back, the late Jake Adams mentioned something about aquascaping rocks being overpriced af, and that you can literally use cinder blocks instead. Is this a thing? I’m planning a 700gal and cement blocks (whole or sawed in half) would make a good base rock. I’ve seen it in a few reef tanks online but it’s not commonplace. I’m only taking it seriously because Jake Adams mentioned it. By cinder blocks I mean cement blocks, where I come from they’re made with local limestone and cement. That’s it.

Cons:
1. Concrete dust… they need to be pressure washed
2. Cement is basic… They need to soak in a bath of water until they stop messing with the pH
3. They ugly

Pros:
1. They’re strong, they’ll never break if you put heavy scaping rock on them
2. They’ll last forever
3. They have holes you can use as shelter if you have large tangs, angels etc
4. They’re cheap as chips
5. They’re very porous
6. You can easily cover them with live rock once the skeleton of the scape is done.

And leaching would almost certainly be a problem.

 

[Tha Reefer]

I like the idea and Originality. As a tribute to late Jake. As proof of concept. Sounds fun. I'm sure you can also be creative in a bridge aquascape. As for practicality. I'm sure we all agree reef rock is the way. No doubt. It will go on sale or find used or damaged pieces. I suggest large PVC pieces for fish to hide and to go with the budget theme. Good luck.

 

[MalteserReefer]

I like the PVC pipes idea. Budgeting is nice but I won’t throw the baby out with the bathwater. In for an penny and all that.

If I wanted to cheap out I wouldn’t be building a 700 gallon xD

I will have to ensure stability of a large scape that’s essentially a honeycomb on the inside for fish sleeping spots.

 

[Doctorgori]

as mentioned, porosity matters. Not worth it IMO besides some of the lower grade dense rock can be had off of Amazon
…also If memory serves me right, I thought GARF or somebody/organization had a method for creating/shaping your own rock from sand/rubble and concrete

 

[MalteserReefer]

as mentioned, porosity matters. Not worth it IMO besides some of the lower grade dense rock can be had off of Amazon
…also If memory serves me right, I thought GARF or somebody/organization had a method for creating/shaping your own rock from sand/rubble and concrete

So concrete can be reef safe?

 

[Doctorgori]

So concrete can be reef safe?

Yes, eventually … whatever that site was (the ones making rock), part of the procedure was they “cured” the pieces in saltwater bins to “bleed off the lime”
I don’t recall everything, I’m stumbling here, perhaps someone will come in and rescue me

 

[Doctorgori]

I found this link
Garf

 

[Mr. Mojo Rising]

I would not take a cinder block from a construction site and put it in my tank.
But I do have cement DIY rocks in my tanks that I made about 15 years ago, nothing wrong with using DIY rockscape.

 

[MalteserReefer]

I would not take a cinder block from a construction site and put it in my tank.
But I do have cement DIY rocks in my tanks that I made about 15 years ago, nothing wrong with using DIY rockscape.

Any instructions how to make them?

 

[Mr. Mojo Rising]

I got the recipe from reef central 15 years ago, but I just googled it now, there are lots of recipes online, just google "DIY reef rocks with portland cement"

It is basically portland cement with either crushed oyster shells or sand (I used sand) and I used the salt method to to create the poressness.