LIVE ROCK RULES: Should the rule for live rock be changed.....again?

[fity2pounder]

My opinion is that you only need enough rock for every fish to be able to hide or have a sleeping spot if not enough you will have stress.

So you are saying that healthy bacterial growth (which, to my knowledge, happens on surface area) is not important? So, according to your opinion, if you don't have any fish (coral only tank) then you don't need any live rock at all?

 

[ca1ore]

1. Are most hobbyists using enough live rock these days and what are your thoughts?

Depends. Do you mean to facilitate adequate biofiltration or to meet a certain aesthetic? If the former, yes, I think the vast majority of reef tanks have enough rock for the biofilter - probably more than they need (though not all rock is created equally).

2. Do you have any "rules" for live rock when it comes to your reef tank?

Yes, I use as much rock as I need to achieve the desired aesthetic (including adequate shelter for the fish population). Then periodically check for ammonia to ensure it is bio-sufficient (FWIW, it always is LOL).

 

[fity2pounder]

I think bio media has become more effective. For example bio bricks or plates. This can allow less rock work within the aquarium.

I've heard stories of these basically just melting if touched...

 

[Dbichler]

So you are saying that healthy bacterial growth (which, to my knowledge, happens on surface area) is not important? So, according to your opinion, if you don't have any fish (coral only tank) then you don't need any live rock at all?

That’s taking what I said and twisting it. If you have enough rock for fish to hide and sleep then there’s plenty of surface area as well. So long as your not using boulders.

 

[Indytraveler83]

Is lack of biodiversity a problem?

I setup my first true reef tank sometime in the 1980s, and used all live rock to do it. (We didn't even realize back then that "dry rock" was an option.) Anyway, I put the LR in my tank, and of course there was die-off, but I think it cured in a few weeks. I knew it was safe to add fish/corals once the water completely cleared, and I could see all the little critters emerging from the rocks: Tiny starfish, amphipods, chitons, isopods, nudibranchs, spaghetti worms, bristle worms, stomatella snails, etc. etc. I also knew the rock contained tons of microfauna that I couldn't see, but I did notice tiny bivalves, bryozoan, sponges, cucumbers, feather dusters, hydroids, barnacles, tunicates, etc. growing all over the rocks.

I'm sure I also got some bad hitchhikers in the live rock, but I don't seem to remember those. (I would have definitely remembered a mantis shrimp. ) But guess what else I don't remember? HAVING TO GO THROUGH THE UGLIES!!! In fact, the first time I ever saw diatoms & dinos was after setting up a tank using all dry rock. I also never quarantined back in the day, and other than Ich coming & going I never really had any fish disease problems. Hmmmm. Could some of these little critters actually be predators of tomonts and microscopic parasites in general?

I once attended a presentation by Tony Vargas (author of "The Coral Reef Aquarium") where he discussed the "European way" of setting up a tank. He uses all live rock, but sets it out of water (on cardboard) for a few hours so all of the "bad hitchhikers" crawl out. The rock is then placed in the aquarium, but is just left to sit & circulate for 3-4 months before adding any fish or corals. (No lights.) You still have to ghost feed, but the reasoning is that this time allows all the little critters/microfauna living in the rocks to propagate without being eaten by the fish. So when you finally do flip on the lights and start adding livestock, this mass biodiversity takes care of many of the problems (like nuisance algae) we commonly encounter in the first year a tank is setup. The tank is already stable, and you don't get "the uglies" because the tiny animals prevent nutrients from ever building up in the first place. And we all know getting a tank off to a good start is one way to ensure it's long term success. I've never tried this approach myself, but it makes all the sense in the world to me.

So how does a sterile tank with dry rock ever achieve biodiversity? I suppose some gets added every time we add chaeto or a coral frag (but only whatever the coral dip doesn't kill). But it takes YEARS to build up to a meaningful level doing it this way. Using all live rock isn't considered practical/environmentally friendly these days (plus the added cost), so what can you do to add biodiversity to your tank? I can think of a few options:

1. Buy some live rock (or even just 1 piece) to mix in with your dry rock. (I'm not saying to buy from here, but this is what I'm talking about: https://gulfliverock.com/premium-deco-live-rock)
2. Buy some mature rock, macroalgae and/or sand from another hobbyist with a healthy, established aquarium.
3. Buy a "reef pack" to add diversity (example here) and/or macroalgae (example here) from a trusted source. Basically, look for critters labeled here as good: https://www.lionfishlair.com/hitchhikers-guide/

Ideally, you would want to add any of the above while still cycling (or at least 6 weeks before adding fish due to parasite tomonts). Fortunately, most of the aforementioned critters are tolerant of ammonia. Even if all you can get is 1 or 2 small rocks, the biodiversity should quickly propagate to the rest of the tank.

1000% this. The best thing I ever did was start my dry rock with "samples" of LR from various sources. I have sponges, bivalves, pods, micro stars, and all sorts of other things I don't see in other people's tanks, and they all started from some "old" rock.

 

[salty150]

Fish NEED rock - live, dry, whatever.

Fish need rock to hide, feel safe, sleep, etc.

Really "troubling" (to be nice) seeing all of these people who want a "minimalist" look to their tank - and have several fish with very little rock.

We are taking these animals out of their natural habitat (reefs), flying them thousands of miles, submitting them to tank to tank to tank handling...

The very least we can do is replicated their new home as well as we possibly can.

 

[X-37B]

My 120 50/50 live and caribsea.
Setup and now 1 year in.
For me it will always be live.

 

[Treefer32]

I would agree if the tank is successful then they are using enough rock BUT that also means fish living a long time. Some of these crazy aquascape minimalist tanks look amazing but where the heck do the fish hide? Where do they sleep? While my tank is somewhat lightly stocked even when I've had more fish in the past, I like to at least provide enough spots all fish can be out of sight should they desire.

Also for me it's live rock ie from the ocean or bust, but you can't get quality live rock anymore so I don't know what I'm going to do when I finally get a dream sized reef tank.

I'm not going to say dry rock or fake rock doesn't work, obviously it does, but it's not for me personally.

I agree with you completely. I have a 350 gallon display and several larger fish (in the 5-8" size area) a total of 15 fish. How many do I see at night? 2. at most. Those two are just night owls. My big black tang that's 7 years old likes to patrol the back of the tank at night, and my Copperband butterfly likes to hang out in one corner in the back at night. That's it, those are the only two fish out of 15 I see within a half hour of the lights going off... Several fish disappear around half hour to 45 minutes before the lights turn off...

 

[Rob62391]

I'm by no means an expert, but when I first started out in the hobby I think the rule was 1lb per gallon and most tanks had rock walls along the back. I think that there have been so many advances in both techniques and just general understanding in a relatively short amount of time that the thinking by some, right or wrong, has changed. My two cents is that biological advances have made is so that we can now take dry rock, add selective strains of bacteria, cycle it, and in time effectively make our own live rock. This coupled with the fact that we now how just an endless supply of equipment effective in removing wastes and organics and the ability to compliment this with dosing systems designed to run uln systems that I don't think the rock really needs to be the main workhorse in nutrient export anymore. That being said, I think that whether your goal is a FOWLR or a Reef you should make sure you have enough to give the fish somewhere to hide out and enough to place corals.

 

[LRT]

I have no idea about the science of it all coming back into the hobby after 15 year hiatus. I think maybe "dry" rock was around back then but I believe "live" rock was the consensus on how to go so that's what I did.
Coming back in 15 years later I immediately filled my system with "live rock" not knowing there where other options. Looking at things now I'm glad I did!
I have 2×65 gallon reservoirs jam packed with 100lbs of Walt Smith Fiji rock and 200lbs of gulf live rock.
I can tell you I have 0 nuisance algae growing on the "live" rock. On about 160 gallon system total. 4 frag tables up top.
Thinking about adding another res and another 100lbs to be honest.

I can tell you I do have 2 frag tables full of nuisance algae growing on the "dry" crushed coral rock I recently placed in my mushroom garden.
I'm still of the old school mindset of using live rock and common sence wise I just cant see how more would not be better for the overall health of the system.

 

[TrojanScott]

Interesting topic and one I'm struggling with right now. I started this hobby almost 30 years ago now, and back then, it was 2lbs of live rock per gallon, 3 lbs if you could make it work. Buying live rock was almost as much fun as buying corals, and it was more expensive. (not now with coral prices) But seeing cured, live rock come in, paying $8-9 a lb for it, and all the life it had, it was an experience for me.

Now, I'm redoing my current tank, and have taken out a TON of rock, both in display, and from my old sump. New sump doesn't have as much room for rock, but I will put some in there. The main display, I'm trying to give the fish more swimming room and have it not look as crowded. I've struggled taking a lot of rock to my LFS and trading for credit. There are pieces I've had years and don't want to get rid of! Stupid sounding I know. Anyway, as others have said, I think the rock is VERY important for fish. I know filtration methods have improved greatly and the need for lots of rock isn't what it used to be, but for the fish... they need places to hide, territories, places to sleep.

Tricky balance. In the end, I will probably have more rock in my tank than a lot of people use now, but old habits die hard. I won't have as much as I once did though.

 

[Treefer32]

One question I have on sufficient rocks is the question of bio diversity. We've gotten so sterile in our lives now, that how clean is too clean? I reused rock that started out as dry rock that was in a 220 gallon system for 3 years. I didn't wash it or anything, it dried in the sun and that was it for a year.

I reused it and cycled my tank for about 6 weeks with Dr. Tims bacteria. I know there's bacteria in a bottle we can buy now, everything from Vibrant (which I was told by the manufacturer that the bacteria becomes inert and ides over a period of time) and others that require monthly or constant dosing. What about bacteria strains that once added live? Vs. needing to constantly be added to the system? There used to be a concept of anaerobic bacteria and aerobic bacteria. I thought it was that the most efficient at removing nitrates and phosphates were anaerobic, but they were the hardest to gain and took years of creating oxygen deprived areas of the tank to get a sufficient population. I don't know how we get the bacteria needed to remove nitrates and phosphates in sufficient numbers to efficiently stock our tanks?

I've seen algae die off when I dose nitrates. It takes off really fast then dies off because the balance between phosphates and nitrates was restored. Does that mean our systems are too efficient causing natural imbalances? One filter is really good at removing nitrates but not phosphates or Visa Versa? What is the recipe to rock, filtration, and chemical balance?

I have 10-16 ppm for nitrates and phosphates test at the .06 - .08 range. I have hair algae I cannot get rid of without dosing something like reef flux. That takes 2-3 weeks then the rock will be clean. Then I'll have an abundance of cyano, then once that's gone, the algae comes back. To me that speaks of an imbalance on a tank going on 2 years established. Does that mean some rocks have trace minerals? A flow issue? That's all the nitrates / phosphates can support is a few rocks with hair algae? Between a skimmer, weekly water changes, algae turf scrubber, and 25 micron cannister filter, I don't know what else to do. My gut says if I double my bio load I'll see the algae clear up. I don't know if that's science or just wishful thinking? The hypothesis I submit is that if the bio load is too low for the system, imbalances with bacterial populations (die off then increase, then die off), mixed with over filtering may lead to continuous algae problems. If the bio filtration were increased and sustained the bacterial populations over time and necessity drove the need for more diverse strains of bacterial populations, then balance would be restored and there would be no nutrients for the algae to consume. Just my thoughts, maybe completely off though. I may simple not have enough rock in my system. I'd estimate around 125 - 150lbs in my 350 gallon display and it looks cluttered as is.

 

[Damian reef boi]

I just have enough rock so my fish can sleep

 

[Damian reef boi]

I just have enough rock so my fish can sleep

 

[Richyreefer]

Trying to find the perfect balance between surface area and channels for flow is not easy. If you use a good quality porous rock and make a nice aquascape, along with rock in your sump you are likely ok. Good hiding places for the amount of stock is a must for long term health of the fish is a must as well.

 

[KLaRue]

The point of porosity has been raised a few times in different responses. Aside from pukani, what are the highest porosity dry rock sources?

 

[Kaboobie]

My thoughts on rock are to have enough to keep the fish comfortable with places to hide and interact with their environment. Have enough to place your coral. But don't have so much rock that you impede the flow of your tank drastically and create tons of dead spots where the flow just craps out. Don't put in so much rock that your coral has nowhere to grow. Granted, I've only been on the salty side of aquarium keeping for a year now. So take my opinions for what you will.

 

[ThePlummer]

This is really interesting and has come at the perfect time for me. I've always been a ton of dry rock, with a piece or two of LR, and just let the LR seed the rest. Again, as others have said, really good pieces of LR are hard to come by now, and with my current WAR on parasites and undesirable hitchhikers, I'm not inclined to use any LR that I haven't been able to physically properly QT.

That being said, I'm currently building a 6' Innovative Marine shallow reef 120. I have about 130lbs of 30 year old Wisconsin rock, that I'm in the process of sawing in half, to silicone to the back of the 120. I've got 6 returns plumbed into the back of the tank and hopefully I can scape the rock wall to minimize or even hide the bulkheads. My plan is to do a minimalist scape in the body of the tank with some branch rock. I figure that the rock wall in the back, with rock in the mid ground will give the appearance of a deeper tank, maximizing the 3D effect. I figure this would also be a great place to place more corals.

As far as creating a large enough anaerobic zone for denitrification, I've always had excellent luck with RDSB's. I always used 5 gallon buckets for the DSB's, but now I'm adding a RDSB in my sump... Hoping to have ample space to propagate enough pods to support a couple of mandarins.

 

[siggy]

Great topic, I started 4 systems, the first 3 was all Alive rock but this last one I started with acid-bleach cured rock and one small Coraline covered mushroom rock, I am having some hair algae problems but nothing that the natural rock had not experienced. Bubble algae has yet to appear so that's a win. I currently have 2 Bio-bricks and have used marine-pur .
I run on the light side, about 50-60,lbs of rock and nutrients are ultra low.120g total sys
Sand carries some load, does bare bottom require more rock or media?

 

[Markscape]

55lbs of well established pukani rock in a 70 gallon. They just don’t make them like the used too

I like most Reef Aquariums but our little bit of Reef look less and less like real ocean reefs. Today a lot have more in common with postage stamp collections than the Great Barrier Reef. For me it’s not about quantity of live rock but about how it’s deployed. For me the best Aquascapes attempt to capture the spirit of the reef - they aren’t just about collecting as many Zoa varieties as possible OR as many Acropora types as possible. Attached is my last Aquascape; I’d be keen to hear your views.