"Live Rock Per Gallon Rule" - Under, Over or Just Right?

BRS

Is this "Live Rock Per Gallon" rule relevant anymore?

  • YES

    Votes: 82 17.9%
  • NO

    Votes: 300 65.6%
  • Yes and No (please explain in the thread)

    Votes: 59 12.9%
  • Other (please explain)

    Votes: 16 3.5%

  • Total voters
    457

ReefRxSWFL

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It depends if you have live rock or imitation live rock. Live rock is not MarcoRock, or Reef Saver, or that tub of rocks at your LFS. And if you want to go without sand, first, best of luck, but you better have well established live rock if you wish to make that attempt. I can assure you that if you took a culture of my rock and/or substrate that there are more than 7 strains of nitrifying bacteria like in brightwell , or Dr Tims, et al. So bottled bacteria cant compete with the diversity found from the Gulf from Tampa Bay down to Florida Bay.
 

eric.tech

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As it has been mentioned, with the advances in filter media tech, I think this rule is dead and gone. Just think about the wet/drys of days past, that was the go to filter back in the day. Now they are rarely used in a reef setting. Fish only set ups do well with them, but as we now know, they don’t quit finish out the nitrogen cycle.

I would agree with other posts that have enough rock in your tank to keep your reef inhabitants happy. Tangs like to graze on “their” patch of algae, eels and marine bettas like to hide, etc. also, can’t forget about pod populations. I’d say a good ratio of rock to what your aqua scape goals are is ideal.
 

Arringar

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With all the nutrient export methods these days it definitely isn’t a must anymore. But a good general rule for noobies imo. Although, I’m a strong believer of the “less is more” as far as live rock prioritizing flow and a balance of nutrient removal through other means.

I'm in complete agreement. This is the best response I've seen thus far... nutrient export relies heavily on good flow which can't be easily accomplished in a tank filled with rock. I don't think the extra surface area of any amount of rock can fully compete with removing nutrient sources from the tank (food, detritus, waste) before they break down. An aquascape that allows proper water flow through all areas of the tank is easily one of the single most important keys to long term success in reefing.

I've been keeping reef tanks for over 30 years. I remember the days when my tanks were filled with huge amounts of rock. The tank never looked "clean", it was next to impossible to get flow through the rockwork without pumps everywhere. And let me tell you, once you put a pump in the back of a tank filled with hundreds of pounds of rock that then gets grown over with coral, you're never getting it out. Pumps fail with time, gunk builds up and eventually you either have to disassemble the scape and clean it up or sit and wait for the algae to grow. I don't miss those days.
 
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CanuckReefer

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I put no because frankly, I have no real idea how many pounds of live rock I have in 140 gallon system. My nutrients are always low and it runs well. I just put in rock until I liked it and leave it at that.

That said I do have a 20 gallon refugium and a good skimmer that runs continuously. If a tank doesn't have those things then that tank would need more live rock.
I am glad I'm not alone here lol... I put it in about 20 years ago (amount upon recommendation of LFS) and a way I went. It's doing its job better than ever now which is good. If I had to guess based on what other systems look like, I'd say around 60-70 lbs in a 90? No refugium or Mech filtration, just skimmer and rock.
 

Bruce Burnett

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It was always a rough guideline as how light and porous or heavy the rock is. Most fish are territorial or like to have a spot to hide and sleep. Yes you can have a minimalist display but if you have various types of fish it is good to have enough hiding spaces. As long as your layout has enough space for placing corals. Same reason I am going back to substrate because I like sand dwellers.
 

sfvmarine

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Today is our QOTD where we feature saltwater aquarium methods, ideas, tricks, equipment, livestock etc. where YOU the viewer will decide if the subject of the topic is deserving of the Underrated, Overrated or Just Right rating! f you have ideas for topics please message me!

Today we are going to talk about the "Live Rock Per Gallon" rule. For many, many years, before all the new filtration technology was available, we had a Live Rock Per Gallon rule and the rule was you needed 2lbs of rock per gallon in your saltwater aquarium. Later is was revised to 1lb per gallon and today it's even less maybe? I've seen successful reef tanks with very little live rock at all. So let's talk about this thing as a whole. Not just how many pounds you should have but is the "pound per gallon" rule relevant at all anymore.

Please rate the following statement as Underrated, Overrated or Just Right.

You should have 1-2lbs of Live Rock per gallon in your saltwater aquarium. Underrated, Overrated or Just Right?

Bonus: How many pounds of LR do you currently have in how many gallons of water?

image via @jgvergo
unnamed (60).jpg
My lfs told me real live rock can be good filtration very porous. The artificial rock we use not so much.
 

GillMeister

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I followed the 'rule' but not intentionally. I just accumulated 250 lbs of rock for my various tanks and when I changed to a 250 gallon system, I loaded it all in there. It's probably way more rock than I need. My nutrients are low, I've got a very nice population of pods and little brittle stars. The hermits and snails seem to keep the rock clean and the fish all have lots of places to shelter. I'm just running out of places for coral.

I could have gotten by with 1/2 this amount of rock.
 

MohH

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Personally, i do not think this is any longer a rule.back in the day when it was realized that live rocks provided the much needed filtration( because of the surface area it provides for bacteria etc) they must have had the believe more is better, however with developments in equipment our filtration systems are ... well even too efficient. Lots of rocks means flow is impeded... may result in more dead spots ... i think at one time hydrogen sulphide pockets was a thing in reef tanks. Also lots of rocks results in reduced swimming area for fish ... especially for tangs angels etc... smaller shyer fish will be ok... i like to see my fish out in the open .... less rocks also, in my opinion allows for better placement of corals ... i can keep rambling on lol.
 

mehaffydr

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I think that it is a good starting point especially for newbies who need some guidance. But what I think is really important is the term LIVE ROCK. so many people are buying and using Dead Rock and is is being called live rock. Its just not the same thing.
That being said I did buy some Marco rock for my new 1100 gallon build but I will also be transferring in about 300 lbs of Fiji and Tonga that I purchased years ago wrapped in newspaper and flown in fresh. I will also be buying 100 or so lbs of fresh rock from Tampa bay.
 

hcoop

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I say no because of all of the advances there has been. I just restarted my tank after taking a few years off with 60lbs dry Marco rock in a 220. Running zeovit I’m at 0 no3(salifert) and .04 po4 (Hanna) in 4 weeks.
 

JCTReefer

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the term LIVE ROCK
Never understood why vendors call this stuff DRY “live rock”.... There’s certainly nothing “live” about any of it. It’s kinda false advertising. Lol. I miss the days of true live rock. I’m just glad I’ve been Reefing long enough to have experienced the good stuff. Newer reefers are at a huge disadvantage in a lot of ways by not having this available. I mean I get why things have changed, but still. Gone are the days, of good ole Indo Pacific rock.
 

Dark_Knightt

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Do what suits your taste and/or budget! I didn't have much money to work with, and I frankly had no idea how expensive this hobby was going to get XD, but I only bought 10lbs of live rock for my 20g, which was still about $180 CAD
 

blstravler

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It depends if you have live rock or imitation live rock. Live rock is not MarcoRock, or Reef Saver, or that tub of rocks at your LFS. And if you want to go without sand, first, best of luck, but you better have well established live rock if you wish to make that attempt. I can assure you that if you took a culture of my rock and/or substrate that there are more than 7 strains of nitrifying bacteria like in brightwell , or Dr Tims, et al. So bottled bacteria cant compete with the diversity found from the Gulf from Tampa Bay down to Florida Bay.
Couldn’t agree more.

The use of imitation ‘live’ rock without adding any true live rock from an established tank or from someone like TBS is what I believe is the missing equation for most new tanks. I also believe this leads to the ugly stage that everyone now says is normal. When I started this hobby you used under gravel filters and got a culture from the LFS of their gravel to seed the bacteria in your tank - worked like a charm. When I went to reefs it was all true live rock.

After a 10 year hiatus from the hobby when I came back it was all imitation ‘live’ rock. I used 80lbs of the imitation stuff and got 10lbs of established rock from a friends tank. I never had the ‘normal’ ugly stage. So regardless of how much rock you use it’s the biodiversity that is missing when people are starting their tanks - ask Ryan from BRS and what he missed about the WWC method.

I just don’t think adding in ammonia and ‘feeding’ your tank gets you to a proper cycle and it likely contributes to the ‘normal’ ugly stage. Also god forbid you add fish when cycling lol. I did all of these things and was told I’d get hitchhikers on the live rock and the fish would die and I’d still go through a ‘normal’ ugly stage. None of that happened.

Just my opinion.
 

mehaffydr

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Never understood why vendors call this stuff DRY “live rock”.... There’s certainly nothing “live” about any of it. It’s kinda false advertising. Lol. I miss the days of true live rock. I’m just glad I’ve been Reefing long enough to have experienced the good stuff. Newer reefers are at a huge disadvantage in a lot of ways by not having this available. I mean I get why things have changed, but still. Gone are the days, of good ole Indo Pacific rock.
Yes fore sure and I think what a lot of people are missing is that yes things like DR Tim's and other bacteria will produce a cycle and will get rid of ammonia but none of then can totally recreated Mother Nature. That's not to be a knock on these products as they are needed but my preference is the real thing
 

KrisReef

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You should have 1-2lbs of Live Rock per gallon in your saltwater aquarium. Underrated, Overrated or Just Right?

Bonus: How many pounds of LR do you currently have in how many gallons of water?
Overrated, and always was. Same scaling problem was used to create another old saw; "1 inch of fish/ gallon" (I think that was a fresh water reference. My apologies to reef purists.)

If I have an established 240 gallon tank with a bubble anemone and pair of clownfish I think 2 lbs should be enough rock to handle that bioload.

I have know idea how much live rock I have in my system. I have one tank that looks like the dreaded old rock pile, (75lbs? 25lbs?) and probably 25-30lbs in the sump. With 15 in the display, I'm less than 1/gallon in a 150 system. That is, I have 150 gallons of seawater and assorted, unweighted live rock that I've collected over the years. :)

No one likes the rock wall tank except the fish that live in it.
 
BRS

If Reefing was a school what letter grade do you think you would be making?

  • A

    Votes: 63 11.4%
  • B

    Votes: 246 44.4%
  • C

    Votes: 180 32.5%
  • D

    Votes: 41 7.4%
  • F

    Votes: 22 4.0%
  • Other (please explain)

    Votes: 2 0.4%
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