The "one inch per gallon" rule
- Thread starter guppy
- Start date
I have used a diffrent method befor. First you find the serface area (length by width). Then for your fish for tropical freshwater 12in. per 1in. of fish, for cold freshwater 28in.(I think it may be 20), and for saltwater 48in. And for fish that go to the serface to breath double the in. requierd.
Welcome to the site! Interesting to see a post from 14 years ago still has traction. I believe the surface calculation model you are referring to was discussed in some detail back when this was first posted back in 2007. Worth a read.
What kind of fish do you have? Tank size, etc?
Why would you double the required surface area for air-breathers? If anything, they would be the least demanding of fish in this regard, rather than needing more.
The whole notion of gallons per inch of fish, or square inches of surface area or anything else, might have some validity if all fish were one inch long. But when a fish grows from one inch to two inches, it has doubled its length...which means that any of these fanciful formulae will call for twice as much gallonage or surface area or whatever...but the fish itself has increased its mass and its bioload by far more than merely double. A two-inch cichlid weighs far more than two one-inch cichlids, utilizes far more food and oxygen and produces far more waste. These formulae are simply far too simplistic to have any usefulness.
The whole notion of gallons per inch of fish, or square inches of surface area or anything else, might have some validity if all fish were one inch long. But when a fish grows from one inch to two inches, it has doubled its length...which means that any of these fanciful formulae will call for twice as much gallonage or surface area or whatever...but the fish itself has increased its mass and its bioload by far more than merely double. A two-inch cichlid weighs far more than two one-inch cichlids, utilizes far more food and oxygen and produces far more waste. These formulae are simply far too simplistic to have any usefulness.
They were looking at firemouths because the lady seen the color of them at a tank at work and she wanted to get some. Haa, firemouths (big grin) a fish I know something about.
Hey guys....this is my first post! Haven't read all these but figured I'd put my 2 cents. I've been doing tanks prob 4-5 years but got sucked in quick, learned a lot and still have lots more to do. I heard this formula a while ago and threw it away. My recommendation would be to just put as many fish as you think looks nice and then maintain it properly. I raise all big catfish and I'm WAY over that number but all my fish cram under a log all day and the tank looks empty. That being said, they're big messy eaters so I have 2 FX6 filters, a Marineland hanging filter, and I'm doing 1 to 2 30% water changes, all on a single 125 gallon tank twice a week. Yes...overkill...but when I look at my fish in there and how healthy they are I smile. ? and if you have a garden hose and a siphon nearby the water change takes 15 mins. Point is...I don't worry as much about the exact biomass in the tank so much as what I need to do to maintain it. Water changes are life, change your filter media, often. Fish tanks aren't meant to sit there for months with no love. If you're trying to figure it out a safe formula for stocking your tank...there is none, just take care of it.
While I am a long way from agreeing with most of this...I don't think 2 weekly water changes of 30% each on a tank crowded with messy eaters is anywhere near adequate, let alone "overkill"...but your last sentence is solid gold.
Many aquarists need to spend more time with a hose and bucket, and less time with a calculator.
