Nitrate problem

[solidsnakejv]

90 gallon tank, 100lbs of live rock in display tank, 15 gallon wet and dry with bio balls. I wanna get rid of the bio balls. I know I have to do it little by little. Question is, do I have to replace then with more rock, or rock rubble?

 

[Ricksreef]

90 gallon tank, 100lbs of live rock in display tank, 15 gallon wet and dry with bio balls. I wanna get rid of the bio balls. I know I have to do it little by little. Question is, do I have to replace then with more rock, or rock rubble?

You need at least one and a half to two lbs of live rock,preferably two to really get rid of nitrates.I would definitely lose the bio balls.IMO

 

[Sergie]

I would steer clear from th 1.5-2 lbs per gallon rule. What's most important is the density and how porous the rock is. The more rock you have, the more "stacking" you'll do, the more surface area of rock will be lost. Isnt the point of live rock for more surface area of rock for water to contact? What is most important is the flow in the tank. With more rock, you'll end up with lots of deadspots, creating "nitrate factories". Lesser rock, more flow, less nitrates. What most have found, is a happy medium between 1-1.75, roughly 1.35 lbs of live rock per gallon would be more than sufficient...never to exceed 1.75 lbs. Too much rock and your base rock will more than likely become dead rock. I can attest to this. I relied heavily on the 1.5-2 lb rule and now all my base rock is dead, while the above rocks are thriving. No need to go overboard, you'll defeat the purpose.

 

[Sergie]

Sorry, to answer the question, I'd go with rubble.

 

[solidsnakejv]

So should I remove the bioballs little by little and once they are all gone replace them
with rubble? Or should I be removing and replacing at the same rate?

 

[Ricksreef]

I would steer clear from th 1.5-2 lbs per gallon rule. What's most important is the density and how porous the rock is. The more rock you have, the more "stacking" you'll do, the more surface area of rock will be lost. Isnt the point of live rock for more surface area of rock for water to contact? What is most important is the flow in the tank. With more rock, you'll end up with lots of deadspots, creating "nitrate factories". Lesser rock, more flow, less nitrates. What most have found, is a happy medium between 1-1.75, roughly 1.35 lbs of live rock per gallon would be more than sufficient...never to exceed 1.75 lbs. Too much rock and your base rock will more than likely become dead rock. I can attest to this. I relied heavily on the 1.5-2 lb rule and now all my base rock is dead, while the above rocks are thriving. No need to go overboard, you'll defeat the purpose.

I agree that the denser the rock,such as Caribbean rock the better.There are different levels of denitrifying bacteria in rock so the denser the better,plus the denser rock weighs more thus takes up less space.Your base rock is not dead just because you don't see growth on the outside of it.You can't see the bacteria on or in the rock with the naked eye,but it is there working.

 

[Grizz]

I would remove and replace at the same rate, trying to keep as much surface area as i could just give it cupple days in between so the BB can catch up

Side note wouldnt the more porous rock offer more surface area like a block 4x4 block of swiss cheese.

 

[Sergie]

Yes it would, that's what I was getting at. A dense rock weighing 10 lb but being the size of a softball, would offer less than a porous rock weighing 5 lbs the size of a softball. That's why that rule is kind of tricky. The more porous, the better, IMO.

 

[Sergie]

And I agree with grizz, remove=replace

 

[Ricksreef]

Yes it would, that's what I was getting at. A dense rock weighing 10 lb but being the size of a softball, would offer less than a porous rock weighing 5 lbs the size of a softball. That's why that rule is kind of tricky. The more porous, the better, IMO.

Not necessarily ,the denser rock has different types of nitrifying bacteria the deeper you go into the rock.It is best to have more of the denser rock and some pieces of the more porous.A lot of LFS sell the lighter rock that takes up so much space but doesn't do as good a job as the denser rock which also takes up less space.Of course IMO and from my own experience.

 

[solidsnakejv]

I'm assuming all the rock rubble has to be submerged unlike some of the bioballs which are not fully submerged, correct?

 

[Sergie]

Correct. It needs to be submerged.

 

[solidsnakejv]

Okay. Thanks guys.

 

[CaptainAhab]

No it doesn't. Live rock is no different (fundamentally) than bioballs. As long as it's kept wet the bacteria live on. Lets look at the ocean as an example. Does the reef or rocks ever come out of the water.. Ahhh yea..

You could easily strap LR rubble to a board and run water over it and achieve the same thing. All that's special about LR is a) it made of calcium carbonate and b) it looks nice in a tank.

If as a society we decided tomorrow that blue balls (uh oh.. will Dragon edit my blue balls comment?) looked better in a tank than LR then the LR industry would be on it's way out and everyone would start touting the need to blue balls to be submerged and how beautiful it looks in all it's blue glory.


BTW: the lighter the rock (in general) the more nooks and crannies for bacteria to live. Lighter the better. That goes for all those who think they get a lot of anaerobic activity in their rock and sand bed too

 

[slitherbomb]

Just get as much LR as you think looks nice.