would the length of the tank make any difference

[Iliveinazoo]

The problem is who is to say what is optimum? I understand that you (RTR) have carried out a detailed study of the F8 and came up with the minimum tank size recommendation but how did we decide what was optimum?

It seems that some people will read the minimum size and then add 20-100litres just for good measure. Some people here recommend 20(US)G long for a Figure 8 which is 5(US)G larger than the minimum Puffer Forum recommendation and others recommend 55(US)G for a GSP which is 25(US)G larger than the minimum Puffer Forum recommendation? Don't get me wrong the more volume that you can give the better for tank stability but if we have these guidelines why not use them? You can always add an additional comment to state that you would provide over and above the minimum.

Sorry Flutter, I'm not having a go at you I've just recently noticed a frustrating trend by many to state an over and above figure.

[RTR]

I can only substantiate info on F-8s, as they are the only puffer I kept in large numbers of individual fish. As for me they are best in light BW (specific gravity 1.003-1.005), the life-cycle costs are not significantly greater for them with conventional biofiltration (live rock is not available in such low density water). Small tank with conventional front to back measurements of 12" are perfectly adequate for turning for them. Increasing the length (side to side) does give them longer swimming room, which allows for higher current along the front wall and sufficient shelter with less current toward the rear of those narrow tanks. So a 20-long (30") or perhaps best a 33-extra long (48" tank) would be optimum. Sumps are needed. With many of these fish I have co-housed them with bumblebee gobies in 20-long tanks or better in 33XL tanks. A veggie filter could be used with either of those set-ups but would be pure personal choice items, offering perhaps a wider margin of safety of upkeep requirements, but is not a requirement.

GSPs are a much larger fish than f-8s. Tanks of 30-long or 40-long are adequate minimums, but the front-to-back spacing is not ideal. A 55 gives only a 1" increase in turning room and by that is better, but is still not ideal. Plus the so-called 55 is the poorest "named" tank we use. Their functional volume never even approaches 55 gallon. If live rock is used in-tank, the water volume is much reduced to the point of inadequacy IMHO. For GSPs I much prefer 75 gallon tanks for improved turning space for the fish and I would still add a sump for much or the LR. I would also add a 24/7 lighted macroalgae refugium with passive return to the display tank. That set-up would have to be full marine (1.021-1.025) for the LR and macroalgae, and also incorporate a skimmer in the sump. That set-up is close to a reef in outfitting, bur upkeep is closer to a FOWLR set up. The initial investment is significantly larger than for conventionally filtered (bacterial biofiltered) tanks, but life cycle total costs are significantly lower due to reduced water replacement costs.

By the way, neither of those tanks are set to duplicate the wild condition of the housed fish. They instead provide pragmatic techniques for long-term upkeep of BW fishes, where we do not know enough about their live cycle in the wild to duplicate it, and have not the techniques for duplicating the complexity of the FW to BW to SW environments.

Life in captivity is not a replication of life in the wild. We simply cannot do that. They have different aims and goals. Hopefully within the lifespan of some current hobbyists we will be able to breed more of the puffers and burfish and will adjust and adapt their optimum care conditions to include this.

HTH

[1puff]

I have 2 f8s in a 30g with measurements 30x12x18.
I think hight is as important as length.
How deep are the waters where they come from?

[fatpuffer]

it is near impossible for most hobbyist to replicate the depth of the water in captive environment.

[warlord238]

your probably right about replicating depth but i also feel that the height of a tank is just as important as the length...sometimes my puffers swim up and down and other times its side to side or just all over, the bigger the tank the better for any puffer in my opinion

[bertie 83]

Yes bigger is better. But I always prefer to go longer, and worry little about height. Unless it's a mixed tank with fish from different tank levels then I opt for a taller tank while maintaining maximum possible length. I always try to understock also. The only fully stocked tank I own is my fahaka tank which is due an upgrade.

[RTR]

For standard midsized hobby tanks (15 - <100 US gallons in my usage), I consider 'length" (maximum swimming distance) far more important than depth (height of the water column). That swimming space's effective length may be functionally increased by having the strongest current in the tank parallel to the front glass. The strength of that current varies with the particular fish being housed.

Swimming up and down against the glass IMHO & IME indicates insufficient swimming space and/or current, or insufficient visual complexity in the tank layout/decor, or insufficient tank size, or improper stocking (incompatible livestock).

JMHO, YMMV