Lace rock: evil?

[DMan5587]

Hi. I have a 30gal reef tank that has been pretty successful. I've just purchased a 225gal tank, and I'd like to cut corners on costs where appropriate (ha).

To this end, are there any detrimental effects (short- or long-term) to using a good amount of live rock (eh 50-75lbs) and a whole bunch of lace rock (say 125lbs)? If I took this approach, I would expect to take my time and let the lace rock mature before adding fish and corals.

If this is just flat out dumb, let me know - I'll lie to my wife and tell her I have a girlfriend - and spend that money on live rock.

 

[WaterDogs]

I've heard bad things about lace rock not worth the gamble, that is why I went all live rock. hth

 

[DonW]

It may have metals imbedded in it. Your better off buying cheap, dry and dead "reef rock" . I forget who packages them but better safe than sorry.

Don

 

[Detri]

What is Lace rock?

 

[Detri]

Never mind found info. I missspelled it when doing a search

On that note. I have seen recipes to make your own.

I think it consists of 6 cups crushed oyster shell to 1 cup concrete. Add as much rock salt as you like for density. Soak in a bucket of water for 3 weeks changing the water every 2 days, to melt the salt in it. I may try to make one and see. Don't think i will add it to my only SW tank. Just curious as to how it will look.

 

[Angelscrx]

Making your own rock is not as hard as some people make it out to be. I know some guys that do it locally and they make nice shapes out of their rock. You can use crushed coral too or break up base rock and add it to he mix. You can make molds in sand or crushed coral too. You do have to cure it as you mentioned and I would probably go longer than 3 weeks just to make sure.

 

[Detri]

Thats cool. Yea I was thinking 3 weeks wouldn't be long enough to disolve the salt in the middle of the rock and clean it out.

 

[mungus]

I believe that the biggest concern with concrete based rock is the ph. You have to let it cure long enough for the ph to drop. Make sure you check the ph before you add the rock to the tank or you may get a huge swing.

 

[MikeS]

I looked into doing DIY live rock (aka "aragocrete") a while ago, but opted not to. There are several issues with DIY LR. First, it's next to impossible to make it as porous as real live rock. Second, the cement itself has all kinds of nasties in it, like aluminium. Third, crushed oyster shells, aragonite sand, ect = phosphate issues....I'd avoid the aragocrete IMO.

MikeS

 

[dnjan]

I looked into doing DIY live rock (aka "aragocrete") a while ago, but opted not to. There are several issues with DIY LR. First, it's next to impossible to make it as porous as real live rock. Second, the cement itself has all kinds of nasties in it, like aluminium. Third, crushed oyster shells, aragonite sand, ect = phosphate issues....I'd avoid the aragocrete IMO.

MikeS

The aluminum in portland cement is in the form of aluminum-oxide, which forms a variety of calcium-aluminate-hydrate compounds when the cement is mixed with water and allowed to cure properly. There is absolutely no free aluminum in portland cement.
As far as porosity is concerned - if porosity is all that important, nobody would ever buy aquacultured live rock from florida ...

As far as lacerock goes, mine is corraline-covered and I have never heard negative comments about its appearance. I don't have any problems with having lacerock in my tank.

 

[Angelscrx]

The aluminum in portland cement is in the form of aluminum-oxide, which forms a variety of calcium-aluminate-hydrate compounds when the cement is mixed with water and allowed to cure properly. There is absolutely no free aluminum in portland cement.

Good stuff to know! Thanks for sharing.

 

[MikeS]

The aluminum in portland cement is in the form of aluminum-oxide, which forms a variety of calcium-aluminate-hydrate compounds when the cement is mixed with water and allowed to cure properly. There is absolutely no free aluminum in portland cement.

Yes, aluminium oxide or alumina is in the cemet, but simply because it is in that form, does that render it any less poentially negative to corals? Aluminium is suggested to biocompound and interfere with metabolisim and photosythesis in corals....would aluminia be any different?

As far as porosity is concerned - if porosity is all that important, nobody would ever buy aquacultured live rock from florida ....

Got the point...but how often do you see Florida aquacultred rock recommended when people ask what kind of rock to get? Most often, you see rock like Fiji, Pukani, ect recommended...many don't recommend Florida aquacultred rock because of the density issues...porosity or lbs. vs volume is very improtant when talking about LR....

MikeS

 

[Detri]

Wow that is alot of information. I am going to have to ask my Dad about the concrete. He'll know alot about the ingredients and chemicals in the portland/cement. I'll try to decifer it and post it here.

 

[dnjan]

Yes, aluminium oxide or alumina is in the cemet, but simply because it is in that form, does that render it any less poentially negative to corals? Aluminium is suggested to biocompound and interfere with metabolisim and photosythesis in corals....would aluminia be any different?

MikeS

The aluminum oxide is bound up in a number of calcium-based hydrates that will not break down into free aluminum without using a huge amount of energy. So, alumina is significantly different from free aluminum in terms of its ability to interefere with metabolism and photosynthesis in corals. You don't need to worry about the relatively small amount of aluminum oxide (typically 8% or less) in portland cement.

 

[DMan5587]

This has been a ton of great information.

Tragically, I think I have more questions than answers! (Damn the torpedos, I'm throwing a chuck of aluminum into the tank!)

Thank you all,
Derek