Live Rock

[andywg]

A quick question on LR. (Thought I'd ask here as you peeps tend to know about LR)

How do you think it would fare in a brackish water setup?

I know that you would lose any of the coralline growth and any hitchhikers, but would it still be able to provide anearobic filtration to lower nitrates?

I am thinking along the lines of an SG of 1.005/1.006.

I understand the rest of the principles (i.e. if added to a tank of this salinity it will cause an ammonia spike).

Thanks in advance

Andy

 

[Ed4567]

I'm not sure there is a straightforward answer to this.

In this article R. Shimek hypothesised that denitrification is possible in live rock due to the action of worms and other small creatures moving water into and out of the rock:
http/reefkeeping.com/issues/2004-05/rs/feature/index.php
I imagine that the majority of worms etc. would die off a a low salinty which , if the above was true, would severly hinder denitrification. However as far as I know the importance of worms has never been tested.

 

[andywg]

If that were the case then yeah, it wouldn't work too well.

I always understood that a large part of live rock's ability to turn nitrate into nitrogen is the fact that it contains anaerobic zones.

If not, no matter, just looking for different ways to do a brackish tank.

 

[Ed4567]

I always understood that a large part of live rock's ability to turn nitrate into nitrogen is the fact that it contains anaerobic zones.

This is true. According to the article, the worms etc. are nessassary to move water to the inside (anaerobic region) of the rock so this can occur.

 

[andywg]

Ah, I see.

Hmm, if only I had the time and money to set up an investigation. I could use som elive rock and see if I can't get the Nitrogen cycle to work by adding a source of pure ammonia.

 

[Def]

Drop CFC a message, I was talking to him about this (he was thinking about trying it) a few months back...

 

[Navarre]

i recently ran my large reef system at a low SG (1.018) for about 6 weeks to help get rid of parasites. I never had any issues with the live rock during this time. Its not as low as you intend to go of course but i hope this helps.

As for worms pushing water through the rock to anerobic zones, well this is possible; perhaps strong flow over the rock would help push the water through, you might also find smaller pieces of live rock to be of help so that the water will findit easier to pass through.
If this is not working then perhaps invest in a denitrator.

 

[andywg]

I was thinking that so long as I have a fairly heavy and well though out turnover it should be ok. When I get round to setting a brackish up up I'll giver it a shot.

I wanted to avoid a denitrator as I seem to recall reading some horror stories about them, don't know how true they are...

Cheers

Andy