Is coral covered live rock still a viable filtration media, or a nutrient trap ?
 

I see many beautiful tanks overrun with enviable corals and want to emulate them. But it makes me wonder about the lr being 'plugged up' as it's covered.

My better half wants me to over populate our rock, and I agree it looks great, but hows it for phosphates and such that may/are trapped in the rock ?
Wouldn't this lead to 'old tank syndrome' ?

Thanks for all input
Let the debate begin ...

Good question. I think it's not really a concern, as most coral encrust a relatively small area in relation to the "crown". Even when my tank was fully stocked, there was plenty of exposed rock surface below the coral.

I think about some of the encrusting pests that I currently have, and they are completely covering the rock

IE; pink/red monti, and all the zoas. Man, there's zoas Everywhere :surprise:

If you need an example I'll post some pics ... my rocks are SMOTHERED

Also, as I think about it, fully mature colonies will utilize nitrogen and phosphorous in there cellular makeup.

I saw a tank on RC that had about 1lb of rock per 10g and 0 nutrients. Big colonies though..

As per my example, I think as more coral grow, the less rock needs to do. You still have a large portion on the undersides that is exposed.

So the corals will use up the nutrients underneath themselves, and then no more nutrients reach the LR ?

I'd like to think that's the case

My guess is yes. I don't stock those types of coral, but many do without nutrient accumulation.

I hope you're right as, for now, I've got all kinds of trapped LR under corals I hope to evict some time this year, and it makes me wonder about nutrients

I'll post some pics in my build thread and link them here ...

Thanks Bradbo

I realise things all balance out in the ocean, and rocks get covered in corals, but how does it affect us reefers ?
No more bacteria ? Trapped PO4 ? No nitrogen activity ?

My tank is rather busy covering the rock right now

Sorry for the crappy pics ... my camera doesn't capture anything well when the whites are off :smile:

http://i749.photobucket.com/albums/x...psixuanry0.jpg

http://i749.photobucket.com/albums/x...psxa3nkri5.jpg

http://i749.photobucket.com/albums/x...psip5dekmf.jpg

I suppose you can answer this better in 6 months :)

I think you should ship it all to me buy new live rock and start over I can test your theory for you

You're both a big help

Glad I'm a Canreef member ...

Jeff, you wanna come here and buy some rock covered in stuff ? Bring money
$2 head

I counted over 200 heads of watermelon (probably closer to 400), and I have a rock with 150-200 heads of candy cane if you're feeling rich :lol:

Plus there's all those sunny d's I haven't counted yet .....

I need money for hardware so bring cash :mrgreen:

If I could I would

Dude I recently spent 400 on coral that crapped out on me this why I'm building a frag tank

I do feel your pain tho

http://i998.photobucket.com/albums/a...e/IMG_0228.jpg

Yup, that's about what my lr looks like

I'm thinkin' about a reset, and a total tank overhaul in the process

I wouldn't worry about it this rock had its own melt down and all disappears on its own except a quarter size chunk only recently it started to grow back and is now a fourth of the rock again. Enjoy the good growth don't mess with what's working

One thing I have concluded about this hobby your tank is forever changing its like the weather every year something different happens good or bad but it still changes

Both those tanks are looking nice. Just think of all the things we WOULDN'T learn if we didn't do at least mini-re-sets :)

Well, let's be honest. You're asking something that can't be answered without guessing. Doubt there are a lot of studies on this, and given the variety of tanks in this condition that may or may not have nutrient issues, and our inability to really say why, the best you can do it see how it works out for you.

Ultimately, your tank will be fine until you hit the given threshold for your nutrient managing properties. So, what rock did you start with? How porous were those particular rocks? How many fish? How often do you feed? What do you feed? Total volume of water changes. Their frequency. Lighting period. Photosynthesis. Respiration. With/without sand to assist? Type and efficiency of skimmer. Do you supplement with carbon dosing?

Given the answers from all this, your tank will be unique and may or may not be able to keep up if/when the rock is fully encrusted with coral.

Does that help more??

My understanding is any nutrients trapped in coral covered rock will over time be absorbed by the coral(s) on the rock if anything I think it's the nutrients trapped under the rock or in pockets created below the rock that are disturbed that can lead to imbalance

But that's my opinion with nothing to support it ....

Having dismantled tanks and seeing these "pockets", I'd tend to agree. I think a design that allows free flow through and under rock is key in avoiding long term issues.
I do think that as a reef grows, you could remove rock as coral mass becomes bigger, with the corals now acting as nutrient export. This is of course very simplified, but I think a sound idea.

I think it depends on what type of corals. I have mushrooms on my lower levels, and no question they trap nutrients. That is very evident when I blow around them with my turkey baster. However, doesn't seem to affect my P04 or N03 levels. They are still consistently near zero. So I think any nutrients that do escape the trap are quickly exported by the skimmer, GFO and bio pellet reactor.

covered live rock
 

Hi,

I have a lot of exposed rock with lots of nooks and crannies and not so much coral. The tank looks great but I need to use Instant Ocean's Nitrate Reducer to keep the algae in check and it does a very good job.

Just saying. I think your tank is georgious!

AquaAddict

I find it surprising that nobody mentions the coral's nutrient uptake. Corals (andby that I mean zoas too) use up nitrates and phosphates to grow. So, if anything, they help the nutrient equation. Sure, there's less exposed rock to harbour bacteria, but one can add rock elsewhere in the system: a refugium, cryptic rock in sump, etc. There's also tons of bacteria in the sand. Why would you want exposed rock in your DT?

I vote for coral-encrusted rocks over bare rock any day....

Pretty sure that was one of my first points :)

Ooops; I guess I should've read the whole thing.

so wait now lol you mean i can use corals and no need for rock then?

I read a journal on RC, guy was pretty much doing that!!

edit: This guy. Forget how much rock, but very little

http://www.reefcentral.com/forums/sh...5&pagenumber=1

i can believe it i have about 20 lbs in a 300g total system for zoanthids :)

i know of a supplier who keeps over 2500 fish (haw too so expensive) with about 50lbs of rock;)

it comes to knowing how your system operates:)

Ya, and that's the key right there. Too many people try to push their system to do something, rather than let it run and just pay attention to what it needs.

The biggest driver in the amount of rock I used was the number of corals I had to mount :)

Yup , I get asked a lot how much rock do you need 1 lb per gallon , 2 lbs per gallon ......actually really not much , you'd probably need more than the ratio to actually build something and mount corals compared to what you need to just work lol

We QT all our fish all last summer when we tore down the bonsai , 5 maybe 7 lbs of rock swapped out every week kept over a dozen fish incuding tangs alive , no sand no skimmer etc. Just that little bit if rock, an air stone and powerhead and a heater or two....the bare basics and did beautifully :)

When I started up I was told as a rule one pound per gallon 4 inches of sand use Dt water for quick cycle

Now it's minimal rock is fine but lots of corals remove all your sand. And Dt water not helpful

This hobby is so interesting and confusing all at the same time. The times they be changing lol

My usual recommendation is half pound per gallon, which is more than enough for filtration and enough for a good layout

That's also what I say to people, start there and add if need be based on what you want to achieve :)


Jeff lots of myths have been debunked over the years which is good , nature of the beast :)

Lol I realize that I just find it comical in another 7 years maybe it will flip back again.