Less Rock?

toddferreira · Jan 17, 2019

Hey so I know the saying is 1 pound per gallon of live rock but I'm wanting to put less Rock in my 90 gallon my question is can I put about 40 lb and a chemi-pure block in the sump will that give me the same as if I were to run the 90 lb

EmdeReef · Jan 17, 2019

1lb is directional. I don’t think I’ve ever kept that much in any of my tanks. Never used chemipure but if it’s like marine pure it will provide additional space for bacteria to colonize. You can also throw some seachem matrix in your sump although probably none of it is necessary IMO.

EmdeReef · Jan 17, 2019

Welcome to R2R!

RobZilla04 · Jan 17, 2019

Welcome!

Short answer, yes. That rule of thumb is more of a loose recommendation anyhow. Today many displays have minimalist aquascapes.

NY_Caveman · Jan 17, 2019

Welcome to R2R! I agree with the above, unless you have a heavy bioload. For most reefs, 0.50 to 0.75 pounds per gallon is fine. If you find later you have nutrient issues, you can always add more rock, or something like Matrix. In the old days people used a lot more and it was overkill. Plus, there are several methods you can use for nutrient export.

PatW · Jan 17, 2019

You could also just get some dry rock rubble and toss that into your sump. But I think that if you rock is well cycled and you don’t feed excessively, the rock should be fine.

reefes pieces · Jan 17, 2019

Also plan accordingly to your livestock with minimalistic rockscaping. Fish need areas to claim for territory, and some more than others. Aggressive and territorial fish should be kept to a minimum. You may want that sweet Domino damsel but might not be a good idea=)

OriginalUserName · Jan 17, 2019

Your plan will likely work just fine. That was the old school recommendation back when nobody had fuges etc. and everybody had super dense/heavy Florida rock.

VR28man · Jan 17, 2019

Many products do the same filtering function of live rock - nitrification and denitrification. I’ve used seachem matrix and marinepure: i recommend matrix highly.

Officially the amount of matrix you use is a function of volume; however i am sure that the amount you need strictly for filtration is also bioload based. I’d imagine the same is true for live rock, I.e. the amount you need is based on the number of inhabitants you have. Also, the porosity of live rock is also a factor in how much you need for filtration.

What this means is that these days you can have a tank with no live rock; The amount you use is based on aesthetics.

SPR1968 · Jan 18, 2019

Hi there and welcome to R2R!

As basically already said, you can have whatever amount of rock you personally prefer in the display but you just need to ensure the system as a whole as enough systems in place to mange the nutrient export by biological filtration methods, so Seachem Matrix (I use as well and it’s very good), Marine Pure etc etc in your sump.

My system is around 650 litres and I have 6 litres of Matrix in the sump, which is enough for 4800 litres, but you can’t have to much biological filtration because it’s self limiting really

toddferreira · Jan 18, 2019

Thanks for all the info guys. Also I was reading back my question I meant Marine pure block not chemi pure Block.

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madweazl · Jan 18, 2019

This is 40-45lbs of BRS dry rock with a single, 5lb piece of Fiji live rock in a standard 75g tank (in hindsight, I'd have liked to use a touch less).

We tend to under estimate just how much space the corals will take up as they start to grow.

NY_Caveman · Jan 18, 2019

VR28man said:
Officially the amount of matrix you use is a function of volume; however i am sure that the amount you need strictly for filtration is also bioload based. I’d imagine the same is true for live rock, I.e. the amount you need is based on the number of inhabitants you have. Also, the porosity of live rock is also a factor in how much you need for filtration.

Funny, Algae Turf Scrubbers are sized based on feeding amounts and it makes perfect sense. Live rock is typically considered in a volume equation. You make a great point here that volume may not be part of the equation at all.

Randy Holmes-Farley · Jan 19, 2019

toddferreira said:
Hey so I know the saying is 1 pound per gallon of live rock but I'm wanting to put less Rock in my 90 gallon my question is can I put about 40 lb and a chemi-pure block in the sump will that give me the same as if I were to run the 90 lb

I would not suggest a MarinePure does exactly what live rock does, but I also expect you can use the reduced rock just fine with or without the block.