Is it the Volume of Water or Size of tank that matters?

[Ridewithme38]

I'm on the very first stage of considering a larger tank for my fish, but the issue is i have a very specific area i can keep it in that limits the footprint i can use...

This tank will end up being for two fancy Goldfish, a Redtop Oranda and a Black Moor, I have an AquaClear 110(500gph), TopFin 30(150gph), 3" SpongeFilter and 4" Spongefilter running in my current tank, turning over my tank water about 24x an hour...i have read that length of tank is more important then depth for Goldfish, but i'm wondering does volume of tank matter?

Basicly the Largest i can go footprint wise would be 37wide by 13 deep....

Within this footprint, there are:

Gallons.......................Width x depth x height
26 Flatback..............36 1/4 x 12 1/2 x 16 5/8
23 Long...................36 1/4 x 12 5/8 x 13
30 Gallon.................36 1/4 x 12 5/8 x 16 3/4
38 Gallon.................36 1/4 x 12 5/8 x 19 3/4
45 Gallon.................36 1/4 x 12 5/8 x 23 3/4

Given "perfect Filtration", why would the 45 gallon be better then say the 23 Long? What benefit does deeper water or more volume of water have on Goldfish when you have REALLY REALLY good filtration?

[Cliff]

I really depends on the size of the fish as a fully grown adults to be able to figure out what size of tank is a best fit. The normal behavior of the fish will also be a factor. Some people have community tanks were they want bottom dwelling fish along with fish that are active and like to swim in the top 1/3 of the tank. In that case the higher tank would be a better fit. Some fish are very active for their size making a longer tank a better fit.

Unless I'm mistaken, Oranda and moors will get 10 to 12" in lenght. Having only a 12 5/8" wide tank doesn't give them a lot of room to turn around. I would say neither of those options would be a good fit for your fish

Maybe something in the range of a 90 gallon (48 X 18 X 24) would be a better fit

[Brhino]

the LENGTH of a tank is important in most cases because fish need to have "room to run". More active fish need more room, regardless of size. Zebra danios only get a couple inches long but they're fast, active swimmers, so they don't do well in a tank without some length to it.

the DEPTH (which in this case means front-to-back, not top to bottom) of a tank gives fish more space and gives big fish room to turn around. Your tank should always have a depth that is at minimum a bit longer than your longest fish (with the possible exception of some long fish that have particularly flexible spines). Don't try to put a common pleco (which can reach 2' long) in a tank with a 13" depth, even if the tank is 8 feet long.

The FOOTPRINT (Length x Depth) of a tank determines how much surface area of the water is exposed to air, and thus how much gas exchange (CO2 and O2 between water and air) can take place. It also gives an overall idea of how much "living space" your fish have, since for the most part fish go back and forth, not up and down.

The HEIGHT of a tank is generally one of the least important dimensions, although certain tall fish like angelfish need a respectable amount of height to work with... although height does influence volume obviously.

The TOTAL VOLUME (Length x Depth x Height) of a tank determines how concentrated the waste your fish are generating will be (even with excellent filtration, there is always an end-product that is not removed except by water changes). The more volume you have to work with, the easier it will be to keep your water clean.

__________

fancy goldfish are not very active, so you don't need nearly as much length as you would for most similar sized fish. Regarding depth, they do get nearly as long as the depths of the tanks you're considering, but a fair part of that length is their flowing, flexible tail fins, so you have some leeway. They are large-bodied fish, so they produce a lot of waste, so you really do want to maximize the total volume of water they're swimming in. For that reason I recommend the largest tank on your list. Now, if you put them in a 23 gallon tank it's not like they're going to keel over dead overnight... but goldfish can live a very long time, and giving them the best accommodations possible is the first step to helping them achieve that. As Cliff says even larger would be better, but personally I think 45 gallons would be enough for two fancy goldfish so long as you provide excellent filtration and keep up with maintenance.

[Ridewithme38]

The FOOTPRINT (Length x Depth) of a tank determines how much surface area of the water is exposed to air, and thus how much gas exchange (CO2 and O2 between water and air) can take place. It also gives an overall idea of how much "living space" your fish have, since for the most part fish go back and forth, not up and down.

The HEIGHT of a tank is generally one of the least important dimensions, although certain tall fish like angelfish need a respectable amount of height to work with... although height does influence volume obviously.

The TOTAL VOLUME (Length x Depth x Height) of a tank determines how concentrated the waste your fish are generating will be (even with excellent filtration, there is always an end-product that is not removed except by water changes). The more volume you have to work with, the easier it will be to keep your water clean.

Thank you!

I plan to keep this tank bare bottom and continue my two 50% water changes(while vacuuming, i'm a bit compulsive, i tend to vacuum up any waste as soon as i see it) a week like i'm doing currently on my 30.25x12.5x18.75 tank, possibly going for two AquaClear 110's instead of one 110 and one 30, if they'll fit(i just wish i could find a left handed aquaclear 110)...when speaking of the end-product that is not removed except by water changes, you are referring to TDS or total dissolved solids, right?

[Brhino]

TDS is sort of an "everything else" category that is independent from the fish themselves, and I understand it. I was referring to nitrate (which is the end product of the ammonia produced by fish after the bacteria in the filter has consumed it) and other fish byproducts like hormones and etc.

[Goes to 11!]

when speaking of the end-product that is not removed except by water changes, you are referring to TDS or total dissolved solids, right?

+ 1 Brhino

As well as removing hormones & nitrAtes, WC also replaces trace elements required by both fish and plants to remain healthy.