Population Question " per gallon

[cirionrc]

Most of you guys think that I have a fairly crowded tank which I am in process of selling my eel and lionfish. In the books I've read, they all say the same thing. Quote - Exotic Marine Fishes by Dr. Axelrod, Burgess, and Emmens, "The safe number in a tank is about THIRTY 2" to 3" fishes per 100 gallons, or 3.5 gallons per medium sized fish", If fishes exceed 3" in size, drastic cuts must be made in number, sot that no more than TEN 4" to 5" fishes could be maintained safely in 100g. A simple filter using only synthetic wool, a little activated charcoal, and on aeration stone could service such a tank.",..........."Thus, a 20 gallon tank can hold 10-20 medium sized fish.", "With heavy filtration and Aeration, doubling or even tripling the estimates to 1 to 2 gallons per medium sized fish." Ok, I have been reading a lot of stuff like this, and to me, his estimates, that is a lot of fish and I have nowhere near of what he is saying. I have heavy aeration and filtration. Biological filtration in 3.5" sand, in 50 lbs. of live rock, and in my biological canister filter. I have a lionfish, snowflake moray, koran angel(didn't know of size they get), and a yellow tang in my 75 gallon right now, which are all in juvenile age right now, except the tang. I know the koran, and eel get hella huge which I will have to sell before they grow huge, but my water parameters stay at 0, ph 8.4, and 20 g refugium keeps my nitrates at 0. Never had any water problems. Why does everyone think my FOWLR tank is crowded? And what about this scheme - 1 dwarf lionfish, 2 clowns, 1 royal gramma, 1 yellow tang, 1 flame angel, and one banded butterfly. Is this too much for 75g? If so, what should I take out of this list?

[tinyreef]

i don't think a lion, snowflake, angel, and tang (all juvenlies) are crazy for a 75g. it's FOWLR, right? how much LR is part of that tho. water volume that's displaced by the LR should be made up for in a sump (i.e. 40% volume displaced by LR should be supplemented by at least a 30g sump). i like using the rough rule of thumb of 5~10 gal/inch of fish. filtration devices allow bending of that rule.

 

but one aspect to remember is the metabolism and body processes of the animals besides their size. tangs poop constantly having long guts to digest the veggies : (vegans!). and the lion & eel are messy feeders. you probably have a very good wet/dry to handle that.

 

either scheme is good if you have the sufficient filtration (sump, wet/dry, skimmer, etc.) to support it imo.

[ross76053]

Everything I read about the proper number of fish per gallon says one fish for every five gallons, but I know there are different opinions.

[reiple]

You can view it in two different angles.

 

First:You keep these animals for decoration/hobby/curiosity or what have you desired for and in the process provide an ecosystem defined by your parameters (budget, space, asethetics, economics, etc.)

 

Second:You keep these animals (maybe initially with the first angle then got focus later) with the desire to achieve an ecosystem defined by THEIR parameters.

 

We all have the ability, the so-called "power" to rule the destiny of these ecosystems we keep. We are either responsible for them or not.

 

Even with a 500 gallons aquarium an eel might still find it small. Imagine placing a man in a 5ft x 5ft x 5ft box. You get the point.

[Glenn]

I agree w/ tinyreef 100%, and just wanted to add one thing: take into consideration a fish's swimming habits also. Some fish are constantly swimming back and forth in the aquarium ( i.e. sourgeon fish) and others are content in certain areas( i.e. clown fish). My tank seems to be the exception. My tang (this is not a nano, BTW!) stays around her hole in the rocks and my damsels swim all over all of the time. IMO your stocking seems fine. Like tinyreef said filtration devices allow us to bend rules.....a little.