Why 1-2 Lbs per gallon. What happens with less?

Glipzcom · 01-09-2007, 08:49 PM

So I always read the same question and roughtly the same answer. And what I want to know is since i dont have that much live rock. What problems will it cause? Or what limits does less have on the health of my tank?

One thought I had was that its a filter so if i have less that means i can have less life in my tank.

Right now my tank already feels croweded to my eye with rock. And I only have probably 30 lbs in a 45 gallon tank.

Thanks as aways guys.

Completely unrelated the youtube addtion is awesome. I need to go start filming stuff in my sea.

Birchell · 01-09-2007, 09:09 PM

30lbs of rock would work. You have to look at it like " the rock is the main filter" for the tank. Just make sure you have enough flow to get the water around all the rock. That will make a huge difference. Im like you, 40-80 lbs of rock would not fit in a 45 gallon, lol. I think some places mark up the lbs per gallon the sell more rock. Im all about using live rock, but sometimes you dont need that much. I would shoot for 1-1.25 lbs per gallon for a tank that will have a decent bio-load. As long as you dont have alot of fish youll be fine. Hope this helps,

Michael

Bruce · 01-09-2007, 10:52 PM

From what I understand, the 1-2 lbs per gal of water is simply a guideline that might help people if they have no idea how much rock to get. Really it all has to do with the density of the rock. If you have very porous then you will need less than if you purchase dense rock.

I would first worry about how you think the aqua-scape looks to you before deciding to get more rock.

I know that if I could, I would probably use a lot less rock and make my aqua-scape more open.

JohnO · 01-09-2007, 11:09 PM

As Bruce wrote, those numbers are really just a guide

Not sure if they are really of much use though as live rock really has no filtration effect at all. You could achieve the same effect with just a normal sand bed and some cured concrete blocks and some PVC pipe so the fish have somewhere to hide.

The real reason we use 'live' rock ( other than the many life forms it contains ) is because of its porousity which means that the inside of the rock can contain the type of bacteria that live in an Oxygen free environment ( as found inside the rock ) and it is that type of bacteria that uses the Nitrate in the water and convert it to Nitrogen. Anyway, that's the theory

John

m_lacom99 · 01-10-2007, 06:19 AM

It also depends on the LR you have. If your rock is very porous it will weigh less than if it was very dense. I have a 2lbs piece that is almost twice the size an other 2lbs piece.

Marc.

Urban_s · 01-10-2007, 06:31 AM

I agree with what everyone else is saying. Personaly I am going to just fill my back wall of the tank and call it good.

coral reefer · 01-10-2007, 08:10 AM

You don't need the 1-2 pounds of live rock for a successful tank! Those guidelines and studies provided not necessary. The main thing is to have a deep sand bed. Your bacteria level should increase to a point based on your bioload even without the added live rock.
As for the wall of live rock in your tank-I would advise against it as the best way to set up your live rock is with caves and whole/breaks in the live rock structure to allow for better water flow and decreased detritus accumulation between the rock work!

inwall75 · 01-10-2007, 08:25 AM

You couldn't pay me enough money to ever have a DSB again. My tanks are either SSB (Shallow Sand Bed) or BB (Bare Bottom). Matt has requested that I'm a little nicer about Dr. Schmuck so I'll leave it at that.

Nitrification is an EXTREMELY quick process and Ammonia Oxidizing Bacteria have the ability to double in population (provided there's sufficient surface area) in less than an hour. When the Berlin method came out (Live Rock and a Skimmer) it made this hobby available to the masses. Funny thing is, all the way back then they knew that the LR was just surface area for bacteria. I have no idea why it changed to having all sorts of neat life for biodiversity.

Denitrification is a much slower process and there's all sorts of ways of solving nitrate problems other than a DSB. Namely, don't overstock your tank and get the waste out before it rots.

I don't like to keep poop as a pet.

Glipzcom · 01-10-2007, 10:33 AM

Awesome guys. Sounds like I am set up right. Althought I do hear that deep sand bed vs barebottom argument. I have about 2 1/2 inches of sand on the bottom of my tank. And I was wondering, right now a lot of it seems to be clumped up by is it the Algae growing down there? This should probably be a sand question. But my astrea snails dont even go on the floor of the tank. And the hermits barely do. I got 3 narsisus snails (man they are tiny) but they like to mostly climb the glass.

I hear a lot of things like stars want to dig under the rocks and make them fall over. is there diggers who dont try to bring the london bridges falling down?

Oh and part of my praise. I have tried other forums but I think the group here is incredible. So thanks guys for being so dedicated. I think you guys are helping me get completely hooked. My girlfriend rolled her eyes saturday when i said I wanted to make a little bench cushion like in church to kneel on as i sit there with my eyes an inch from the glass staring at everything.

m_lacom99 · 01-10-2007, 10:35 AM

Give some cerith snails a shot... I have a bunch and they will mostly stay in the sand and clean it out.

Marc.