Live Rock Busted!!

[csababubbles]

I set-up a 30 gallon tank in September. The tank houses a spawning pair of mundoon blennies, 4 sexy shrimp, and two snails. The tank has no live rock, no sand, only a realistic-looking ceramic cave structure. There is no skimmer, only a heater, tunze nano powerheads and a surface overflow. The only natural thing I have added to this tank is a ball of cheato that I took from another of my established tanks. I'm sure the cheato had lots of pods, microstars, and algae spores and such with it so that introduced some life to the tank.

Nitrates are at 0. That's right, no live rock, no sandbed, no skimmer, no macro algae harvesting, no fuge, just flow and algae. I think this may very well prove that live rock and sand are not need for denitrification. The nitrates have to be going somewhere. Only thing I could think of is that there must be some sort of really thin layer of bacteria over every surface area of the tank that is making use of this energy. The algae (both micro and macro) should also be using it up and converting it. But the main point is that there is a constant input of food from me and this waste has to be going somewhere because I am not exporting anything and I am only doing 20% water changes once a month and according to my calculations that should not be having any sort of significant effect on the system.

Aside from the introduction of natural fauna to our systems (which could be accomplished in much better, efficient, and inexpensive ways), I don't see the big advantages of using live rock and sand, aside from aesthetics.

I can't be the first person to run a reef tank long term without sand and live rock, so am I missing something in my experiment or overlooking something?

 

[jezzeaepi]

Well having two fish that dont eat much by themselves ina 30 gallon certainly helps hehe. Throw in a few more fish or something in that requires more frequent feedings and I am sure youd start to notice some problems.

Case and point-
Ive been having nothing but problems with my tank for 4-5 months because of not having enough live rock in the tank. Things werent stable and none of my coral have been happy, even though my nitrates have been only around 5-10, and my phosphates have been below .05 and everything else about the water tested fine. I added another 60 pounds and theres a night and day difference in the tank. I think there is somehing more at work then just keeping the nitrates down.

 

[Chichas01]

I'm not sure 9 months counts as 'long term'. But hey, let us know how your experiment goes.

 

[csababubbles]

Two active 4" fish is definately a significant load for a 30 gallon tank. I'm not saying that this particular set-up can support a much larger load, but what I am seeing is a set-up that does not include the usual live rock and sand-bed yet there is no nitrite or nitrate measured with my test kits. Seems to be the work of a bacterial film as well as the algae.

When I say long term I meant to imply that the tank had gone through its initial ammonia/nitrite/nitrate cycle, continued through the various algae blooms, and has settled down and on its way down the slow road of maturation.

 

[Scooterman]

I run a QT set-up with nothing in it, easy to keep a couple fish, the LR & sand are for bigger systems & just a supplement to WC's and skimming as part of a filtration system allowing a larger bio-load. Nothing to bust IMO!

Also, If you have spikes, you'll be lucky to catch one on a test, that is why they are called spikes but under that load with a few wc's alone should be fine. As you said bacteria will show up somewheres.

 

[mmn_usn]

As for bio load, I have always heard that the max bio load in a tank is 1" of fish per 1 gal.. with that thinking your bio load is very small considering what it could have. 8" worth of fish vs 30" of fish... Just my 2 cents

 

[csababubbles]

well its enough to prove that the bacteria and algae present on the surface of the interior of the tank is enough to support a significant fish load without the help of the denitrification that we assume is taking place inside live rock.

 

[Herefishyfishy]

only a realistic-looking ceramic cave structure.

Perhaps this structure has more surface area than you assume

well its enough to prove that the bacteria and algae present on the surface of the interior of the tank is enough to support a significant fish load without the help of the denitrification that we assume is taking place inside live rock.

The key omitted word is "currently"

Almost anything is possible in a tank, the question is how stable is it and how much buffer against any unforeseen problem it has.

"Shrimp happens"

Best of luck with all,
Mike

 

[tike]

I can't be the first person to run a reef tank long term without sand and live rock, so am I missing something in my experiment or overlooking something?

Uh.... sorry to tell you but that isn't the definition we all use as a "reef" tank. You have a marine tank with fish and inverts. I am sure you will still get the results you claim with maybe a small spike here and there. Let's see an experiment with corals added to it and see the results from that. Then i'll be a little more convinced on whether you need live rock to keep and maintain a healthy reef tank.

 

[csababubbles]

Herefishyfishy, yes the cave has a lot of surface area but much less then the porous live rock we use in our tanks. perhaps denitrification that we assume is taking place inside the pores of the live rock can also take place in a sort of bio-film on all the surface area of the tank.

I don't know what you mean by the word "currently". Do you mean our "current" thinking of how live rock functions in our tank or whether my tank is only "currently" supporting my fish but we'll see in the future?

tike666, the tank may not be the definition YOU use to define a reef tank but who is to say your definition is correct? the tank has marine macro algae, micro algae, snails, pods, marine fish. I'm pretty sure it fits in the general category. I have not introduced corals yet but why do you think they would have any sort of significant effect on this experiment and its goals? Maybe you misunderstand where I am going with this experiment. I don't think we need live rock at all is what I am trying to prove. i don't think there is any sort of significant denitrification going on in live rock. Its either being converted near the surface of being used by the algae present. As for providing shelter for fish, they dont know if its live rock or fake rock. Algae does not care where it grows, as you can see it will grow not only on live rock but all over plastic, glass, etc. If your concerned about the variety of life it brings with it, trust me there are much better ways to bring in an assortment of life then the way we currently import our "live rock" you see for sale.

 

[Herefishyfishy]

My comment on the omitted "currently" is that your tank is "currently" balanced and apparently doing well. With so little margin for error on nitrification, keep your fingers crossed and keep up the excellent water changes.

Live rock isn't "live" due to hitchhikers and critters attached, it is live with nitrifying bacteria. Can start with dead base rock or import some live and cure it.

Whats going to happen when you want to clean the glass or add a fish?

Glad you are enjoying this fine hobby with it's infinite possibilities, and thanks for sharing.

 

[gotfish]

I'm not saying I would do what you are doing, but it's your tank, your fish and your decision. There is another forum that I'm on that has a guy who almost does the same thing, but a bit more extreme. He's on the very very low tech side of the hobby. Meaning no water changes, no filtration, no heater. He's successful with both fresh and salt water. He doesn't even treat his water. He believes in the power of plants to clean and treat the water. Now, the pics of his tanks look a little weird, but it works for him. If you're happy with what you're doing and the fish are healthy, keep learning and experimenting. There is always more then one way to skin a cat.

 

[tike]

I don't think we need live rock at all is what I am trying to prove. i don't think there is any sort of significant denitrification going on in live rock. Its either being converted near the surface of being used by the algae present.

Nor did we need rock 25 years ago when I was keeping marine aquariums, now the only difference is the live coral. Coral tends to be very sensitive to param changes where as fish and inverts I have personnally kept in water with trates as high as 100ppm! What I am saying is add in the piece of the puzzle (corals) let the system run awhile and then....perhaps.... Live rock will be busted.

 

[csababubbles]

Right, many fish can live in water with 100 ppm nitrates. Even nitrites are not harmful to our fish at the pH we keep our tanks. But anyways, I will let the system run quite a few more months before corals to allow the tank to mature.

 

[preons]

whats in there to mature? the walls? the pumps? I bet they are already there dude.

 

[csababubbles]

i meant let the microfauna develop/increase, not to mention that i think there is still potential for mini-cycles and such so I think its good idea to let the tank be as it is for now.

 

[mattleycrue76]

:lolass the popcorn:lol:

 

[morgan]

if u take a tank and but good live rock (that is availble in australia) its full of micro fauna corals hitchhikers and various differnt coloured coraline algeas u wont even have a cycle u can add corals 2 weeks later and fish after 3 weeks and u will have a bueatiful reef tank

to say rock dose nothing is wrong it dosent complete the nitrate cycle completely thats why people keep fuges and have nitrate reactors

how often do u dose the tank and where are your pics theres alot of talk but no pics to prove the point, hwta it sounds like u have is a fuge with no display

 

[ret25yo]

with live rock we (consumers) are paying for:
the look
the different TYPES of nitro bacterias
variety of life present on "reef rock"
possibility of a really nice hitchhiker (like a pack of Baseball cards)

your tank ...your choice

 

[ret25yo]

p.s. dont forget that your types of microfauna and algaes will constantly compete and the wrong one has a better chance to prevail .....(hair,cyano)