Grotto (sp) Rock

[Miss Wiggle]

well, we've been contemplating setting up a marine tank so last weekend we went to an excellent marine specialist near us. He talked us through shed loads of stuff which baffled me a bit, we've decided not to go ahead with it as we just can't justify spending that much at the moment as we've loads of stuff we need for the house and Ian needs to save for a new car

Anyway the bloke was telling us about grotto (sp?) rock, works sort of like live rock and complete's the nitrate cycle and can really help filtering your tank, said it worked for tropical tanks too. Can anyone explain it all for me and let me know if it could be of any help?

Thanks

 

[Miss Wiggle]

bump anyone?

 

[The-Wolf]

I can't find anything on google, even froogle only shows a seller with no info on it. any chance of a pic so we can try and help you better?

 

[Miss Wiggle]

I can't find anything on google, even froogle only shows a seller with no info on it. any chance of a pic so we can try and help you better?

hmm i might have the name wrong, sure it was along those lines, might give the bloek at the fish shop a ring and ask him!

Haven't any pics as I didn't get any, was just curious about it really.

 

[Miss Wiggle]

rang them, it's deifnately called grotto, can't find bugger all about it though

just this on ebay, no info but some pics

http/cgi.ebay.co.uk/FULL-MARINE-SET-UP_W...5QQcmdZViewItem

 

[juliehainsworth]

The rocks in that tank look like the porous ones used in bio orbs (apart from being larger)! If thats the case its because they're porous that helps them to form homes for the good bacteria like the sponge in your filter! This is because with them being porous they have a larger surface area for the bacteria to grow on! (someone please correct me if I'm wrong)

 

[Miss Wiggle]

The rocks in that tank look like the porous ones used in bio orbs (apart from being larger)! If thats the case its because they're porous that helps them to form homes for the good bacteria like the sponge in your filter! This is because with them being porous they have a larger surface area for the bacteria to grow on! (someone please correct me if I'm wrong)

yeah we saw some of the little rocks they use in bio orbs the other day and they look just the same, they weren't calling it grotto rock though, not really sure what it was they called it though.

It was something to do with it being porous, he was saying about the cycle being amonia >> nitrite >> nitrate just like the filter does.... then it does another step which I can't remember and that keeps your nitrate levels down and reduces the need for water changes just like in marine tanks where you just top up instead of taking water out.

 

[juliehainsworth]

Are you going to get some and give it a go?

 

[Miss Wiggle]

I'm contemplating it.... want to know a bit more before I try it though. Don't like just taking one person's advice, specially as it's form a lfs I've never been to before.... they do *seem* really good, but you can never quite tell from 1 visit can you?!

 

[juliehainsworth]

Which LFS was it? Please dont say Living World? You could always ask at Pet City or Paws for Thought I know at Paws for Thought they def have it as thats how I realised what you were on about!

 

[Miss Wiggle]

Which LFS was it? Please dont say Living World? You could always ask at Pet City or Paws for Thought I know at Paws for Thought they def have it as thats how I realised what you were on about!

ha ha nah, i live just down the rd from the living death, never go there!!

It was a marine specialist called The Reef Ranch in Seacroft or somewhere like that.

I'll ask paws for thought this weekend then, they're really helpful in there too.

 

[andywg]

I would be very careful.

Sounds a lot like lava rock which is of little use in a marine tank.

While Natsuko is right about there being plenty of area for bacteria, you want more than that with Live rock, you need it to create anoxic zones for nitrifying bacteria to live.

It might be reef bones, or "dead" live rock which is fine as it can be recolonised by the bacteria. The problem is ensuring it is porous enough to allow anoxic zones to develop in the rock. Things like lavarock are too porous and the oxygen level stays too high for the nitrifying bacteria to develop.

If it is reef bones, then you are laughing as it is a cheap way of getting more LR in a tank (so long as you are very patient at stocking).

I would feel better just doing DIY live rock. It costs me about 50-75p per kilo to make and I know that it works well (and you can make any shapes/sizes you wish).

 

[Miss Wiggle]

I would be very careful.

Sounds a lot like lava rock which is of little use in a marine tank.

While Natsuko is right about there being plenty of area for bacteria, you want more than that with Live rock, you need it to create anoxic zones for nitrifying bacteria to live.

It might be reef bones, or "dead" live rock which is fine as it can be recolonised by the bacteria. The problem is ensuring it is porous enough to allow anoxic zones to develop in the rock. Things like lavarock are too porous and the oxygen level stays too high for the nitrifying bacteria to develop.

If it is reef bones, then you are laughing as it is a cheap way of getting more LR in a tank (so long as you are very patient at stocking).

I would feel better just doing DIY live rock. It costs me about 50-75p per kilo to make and I know that it works well (and you can make any shapes/sizes you wish).

it's not for a marine tank though, the bloke said it could eb used in tropical as well which is what I wanted to know about.

Thanks for your comments and help though.

 

[andywg]

It will still need to create anoxic zones for a tropical tank.

The only successful introduction of these I know of in FW is with nitrate reducing filters that have a pump controlled by a redox meter that changes the current going through the filter based on the oxygen levels therein.

That is not to say that these rocks don't work, just it is not that likely, especially when you consider the flow rates needed in marine to keep the LR working correctly, most FW tanks would not appreciate 20x turnover and higher.

Also remember that a marine tanks has a far lower biolad than a FW tank and even then, when crammed full of LR it is still hard to get 0 nitrates without macroalgae or deep sand beds or other filtration.

Could be worth an experiment, but I wouldn't spend any decent amount of money on it if I were you.

 

[confusion]

grotto rocks, IIRC, are more commonly called tufa rocks. It's a type of volcanic rock that is pretty porous and becomes a colony for bacteria. I've read that some types of rock (not this in particular) will absorb nitrates. They can only absorb so much, and presumably if the "ambient" nitrate levels drop in the water, the rocks will start releasing their store of nitrates.