Whats the correct lenth of fish per gallon?

Question

I look and ready alot of stuff for how many fish you can have in a fish tank , i know it goes by the lenth when they are fully grown but does anyone really know how many fish you can have in a tank or the lenth of fish per gallon , I have reed that it is 1.5 in per 7.5 gallons of water and other numbers also , my pet store says 2 inches per gallon of water , And the other pet store across town tells me 1 inch of fish per gallon of water does any one really know

3 lionfish
1 naso tang
1panther grouper
1 morish idol
1 foxface
1 clown trigger
1 dottie back
4 diamond gobys
1 yellow eyed tang

fish only tank 160 gallon

i have never had a fish problem with any of these fish getting along and some of them i have had for 3 yrs the lionfish dont bother the gobys at all, or an of the other fish

All fish are in a 160 gallon tank with 2 cascade 1500 filters one bio wheel filter 6 powerheads 2 uv sterlizers and protein skimmer , i have salt water fish for a long time but this question comes up in my mind all the time and most people dont seem to know

Clown trigger is is about 2 yrs old and my lionfish are about 3 yrs old

Answer 1

Length of fish per gallon is not a valid method of establishing stocking rates. It depends on the total bio-load of the organisms in the tank. It also depends on how well and often the maintenance regimen is done. Your filtration system seems adequate for the level you currently maintain.If your system is not well maintained you will have problems,if you are particularily dilligent you could add more livestock. Most people that ask this question have another pet in mind.The answer is you've got to decide how much time you are willing to devote to caring for your fish. How old is the Clown Trigger? Sooner or later he'll start pestering the Lionfish.Good luck.----PeeTee

Answer 2

There isn't a good rule that states how many fish per gallon since each species requires different amounts of "space" Also you are running a salt tank. Rock and corals with other decorations will displace water so a tank that is 55 gallon with 40 pounds of live rock is no longer a 55 gallon tank. 3 lion fish although some "web pages" will say need 55 gallons each does not apply when keeping 3 in the same tank. Just as your tang and panther grouper.

Your tank is fine with the fish you have. This still allows room for proper growth, however your grouper has the capasity to get very large. I would add no additional fish.

The 1 inch of fish does not apply in any way to salt fish. However if you are looking for a good ratio for salt is 2" of fish per every 5 gallons of water. That is to say the tank is over a year old and established.

More fish can be housed in salt with a good skimmer than in the freshwater same.

Answer 3

There is no exact way for saltwater or freshwater (the 2-3 inch per gallon SW is a place to start). Measuring dissolved oxygen is a good determining factor, saltwater holds 42% less oxygen than freshwater, temperature also affects your dissolved oxygen level. A dissolved oxygen level of 5-7 ppm is sufficient.

Other factors to consider:

*The amount of surface area relative to the gallons of water the aquarium holds. I have observed many tall narrow aquariums over the years of my maintenance service where the filtration and other factors were equal to comparable sized and stocked rectangular aquariums, that general fish health and longevity were lower.

*Filtration, a properly filtered aquarium (good bio filtration, good mechanical filtration, and good circulation) with multiple filters is important.

*Maintenance schedule that includes regular efficient water changes

*Well maintained water chemistry (including Alkalinity and Redox)

*After proper feeding, good cleaning routines, proper feeding routines, good filtrations; If after all these are checked off and you still have nitrates that struggle to stay below 30 ppm, you probably have an over stocked aquarium (especially if there are live plants!). Also a kH and pH that starts out at proper levels, but then drops quickly after water changes and/or addition of stabilizing chemicals.

You obviously have experince, so you are going to have to be the ultimate jusdge of your fish health and well being (based on your observations). You also have an excellent filtration system, if only all marine aquarists had what you have!

For more saltwater basics, here is a good article:
http://www.americanaquariumproducts.com/Basic_Saltwater.html

You might read this article for more info about test kits such as kits for dissolved oxygen:
http://aquarium-answers.blogspot.com/2007/02/aquarium-test-kits.html

Answer 4

I was always told that in a saltwater tank it is 4 gallons per inch of fish and 1 gallon per inch in fresh water.

Answer 5

I'm pretty sure that it's 2-3 inches per fish per gallon, but before you get these fish, you need to check some compatibility because I know for sure that you can't put some of these fish together (Lions and gobies aren't compatible)....Try this website. It will tell you on each fishes page how big the aquarium needs to be per fish and it also has a compatibility chart. http://www.liveaquaria.com/product/categ.cfm?pcatid=15

EDIT: The girl's answer underneath mine is for freshwater fish...yours will be saltwater so her answer isn't correct for your situation.