1" Of Fish Per Gallon Rule?

[Steve H.]

Hi All!
I know that the 1" of fish for every gallon of water is just a good practical starting point, and is not a rule written in stone.
But does this rule apply to the amount of water to sustain healthy fish, or size of tank for healthy fish growth? Or a little of both?

The issue is I have a stocking list in mind, and I am trying to figure out the best tank for me to invest in.
Also, trying to get at if adding say a 50gL sump would increase this rule. For instance: if I had a 90gL tank with a 50gL sump that would give 140 gallons of total water volume.
Would this general rule apply to the 140gL, or still just the 90gL?

There is a 60gL tank that has the depth I want, but not near enough volume for my stock list.

A 75gl with good length, but not enough depth or water volume.

A the 90gL with good depth and length but just short on volume.

And the 125gL which has the water volume I would need, but is short on the depth I want also is a little longer than I would like it to be.

Thanks for any insight here!

 

[onidrase]

the 1" of fish per gallon rule is a really bad stepping stone, honestly. It -works- in a sense that it might make people a little more weary of what they add to their tank at a certain point, but stocking is a pretty complicated thing, which can only be judged by what fish you're stocking, rather than how many inches of fish you get.

Just a few examples here

There are a lot of aggressive fish out there, some of them prefer to be kept in a large group of other aggressive fish to help break up the aggression and avoid any singling out in bullying (like African cichlids, and aggressive schooling fish like piranhas) which will likely require an overstocked fish tank. and some prefer not to be in groups, and will act out at fish that invade their territory, so stocking must be made to make sure other fish will not enter territory often, if ever. Even though this fish may be 6 inches to well over a foot long, you might not be able to stock a whole lot with it.

There are also fish out there that are pretty bulky and produce a lot of waste, like most algae eating catfish. These fish will produce a higher bioload, which will thereby produce more ammonia than say, a school of neon tetras equalling the same size in inches as the pleco.

Some fish are also much bulkier than others in size in general, look at bleeding heart and black skirt tetras, reaching into the 3 inch mark, in comparison to the red eye tetra, also reaching the 3 inch mark. The black skirts and bleeding hearts get much more round in shape, though they all reach the same size in inches.

You also need to look at the areas in which fish swim. If you're technically overstocked with a bunch of middle and top swimming areas, you shouldn't be reluctant to buy a school of cory cats or maybe some loaches, they occupy a different area of water space.

My main tank right now is a 37 gallon tank with a 75 gallon filter attached on the back, it has a firemouth, 9 black skirt tetras, 6 red eye tetras, and 5 khuli loaches. That's 71 inches of fish, so I'd be nearly doubling the amount I should have according to the 1 inch of fish rule.


Stocking is really a "be your own judge" thing. Within Reason, of course. That doesn't mean you should go out and buy 40 guppies for a 10 gallon tank. It all depends on what fish you're keeping, and how much water changes you do. The most important thing about stocking is that the fish you buy aren't too big or aren't going to be too big for the tank you provide. Do your research around the forums or around google for the fish you want before you buy them. Just give us the name of a fish you want, throw in your tank dimensions, water perimeters, and fish already in the tank, and we'll be happy to help out.

 

[Steve H.]

Thanks! I've been doing some research for quite some time, and I am still probably 3 months from when I plan to start this project. And, I think I won't have the tank to my ideal stocking point for 6 to 8 months from now.

Here is the project I have in mind:
(High end is where I will start Low end is a guesstamate mortality rate end point)

8-10 Julii Cory's
6-8 Bolivian Rams
12-15 Marbled Hatchets (on the fence here. Maybe cardinal tetras)
6-8 Discus

Everything I have read the Discus need minimum 5gL each. So, there is 40gL right there.
I know the Rams are territorial and need minimum 5" of tank length each to call there own.
The Discus also need space and places to hide to not feel stressed.
The Cory's also need space on the bottom to call there own

But through all my research so far this group seems to be compatible in needs, tank space I think they would go good together.

I would like to go with the 90gL which is 60" long and 24" deep.
Do you think my stock list would fit?

 

[TwoTankAmin]

The discus will need more like 10+ gals each.

Hatchets wont really work well, go with some cardinals. Just don't start with small cards and big discus. Hatchet fish are jumpers. in the wild to escape a predator they leap out of the water and sail across the surface to escape. It is often suggested that one lower the tank water level and also use floating plants.

 

[onidrase]

Thanks! I've been doing some research for quite some time, and I am still probably 3 months from when I plan to start this project. And, I think I won't have the tank to my ideal stocking point for 6 to 8 months from now.

Here is the project I have in mind:
(High end is where I will start Low end is a guesstamate mortality rate end point)

8-10 Julii Cory's
6-8 Bolivian Rams
12-15 Marbled Hatchets (on the fence here. Maybe cardinal tetras)
6-8 Discus

Everything I have read the Discus need minimum 5gL each. So, there is 40gL right there.
I know the Rams are territorial and need minimum 5" of tank length each to call there own.
The Discus also need space and places to hide to not feel stressed.
The Cory's also need space on the bottom to call there own

But through all my research so far this group seems to be compatible in needs, tank space I think they would go good together.

I would like to go with the 90gL which is 60" long and 24" deep.
Do you think my stock list would fit?

Discus tanks aren't my specialty, but I can tell you to make sure you have the time, money, and commitment for their tanks, they're a bit more touchy than most fish.

I'm actually, for a change, going to recommend german blue rams instead of bolivian rams, as discus appreciate a higher tank temp of 86F, whereas bolivians prefer more around 77. GBR's prefer it in the 80's as well, so they're a better matchup, though I'd ask somebody else who knows more about discus tanks.

Devoted To Discus on here is definitely a pro with discus related things, I'd go look for him.

Cories are also more of a social schooling fish, they don't need space for their own. With a 60" long tank, you could probably get a lot more, if they are compatible with the temperature preference.

 

[Steve H.]

Thanks! I've been doing some research for quite some time, and I am still probably 3 months from when I plan to start this project. And, I think I won't have the tank to my ideal stocking point for 6 to 8 months from now.

Here is the project I have in mind:
(High end is where I will start Low end is a guesstamate mortality rate end point)

8-10 Julii Cory's
6-8 Bolivian Rams
12-15 Marbled Hatchets (on the fence here. Maybe cardinal tetras)
6-8 Discus

Everything I have read the Discus need minimum 5gL each. So, there is 40gL right there.
I know the Rams are territorial and need minimum 5" of tank length each to call there own.
The Discus also need space and places to hide to not feel stressed.
The Cory's also need space on the bottom to call there own

But through all my research so far this group seems to be compatible in needs, tank space I think they would go good together.

I would like to go with the 90gL which is 60" long and 24" deep.
Do you think my stock list would fit?

Discus tanks aren't my specialty, but I can tell you to make sure you have the time, money, and commitment for their tanks, they're a bit more touchy than most fish.

I'm actually, for a change, going to recommend german blue rams instead of bolivian rams, as discus appreciate a higher tank temp of 86F, whereas bolivians prefer more around 77. GBR's prefer it in the 80's as well, so they're a better matchup, though I'd ask somebody else who knows more about discus tanks.

Devoted To Discus on here is definitely a pro with discus related things, I'd go look for him.

Cories are also more of a social schooling fish, they don't need space for their own. With a 60" long tank, you could probably get a lot more, if they are compatible with the temperature preference.

Thanks again.
DTD has inadvertently counseled me in several steps of my research for this tank. Mostly about maintaining water and water parameters.
I will have to ask about the base temp for Discus. Everything I have read stated that you want temps in the mid 80's (84-85) for breeding or growing on stages. And a temp of 82 is fine for keeping adults.
I kind of based the whole stock list on the 82 degree temp. With my only real worry being the Julii Corys...the only Cory that can tolerate an 80 degree temperature.
In actuality the whole stock list came from a site I have used in my research called Discus Madness.
Where they listed excellent tankmates for Discus, and all I really had to do was chose the ones I liked based on top, middle, and bottom dwellers.
I will look into the GBR's, but heard they're to aggressive. But I haven't studied up on them at all.

Thanks again.

 

[onidrase]

I wouldn't find them much more aggressive than bolivians. Most dwarf cichlids are pretty docile.

 

[Steve H.]

The discus will need more like 10+ gals each.

Hatchets wont really work well, go with some cardinals. Just don't start with small cards and big discus. Hatchet fish are jumpers. in the wild to escape a predator they leap out of the water and sail across the surface to escape. It is often suggested that one lower the tank water level and also use floating plants.

Thanks TTA!

Cardinals are my original choice because I read in one place they were top schooling. But read somewhere else that they were mid to top dwelling, and then saw they actually go everywhere and anywhere in the tank.
Only changed my mind to the Hatchets because they fit the water parameters I'm looking for, and they tend to stick to the top.

Still undecided about my top dwellers....

 

[TwoTankAmin]

Serbai corys will work fine with discus.Here is a nice thread from PlanetCatfish discussing warmer water corys http/www.planetcat...php?f=6&t=31250