20L vs 29?

[NoNitrates]

So a 29 has 45% more water than a 20L. But 0% more surface area. So can you stock a 29 with 45% more fish or is it closer to 0%?

 

[Masha]

Guessing here-
If you have enough circulation in your tank, bringing that larger volume of water in contact with the surface, both tanks will be fine in terms of oxygen content.

But the fact that wastes from x number of fish are more dilute in a larger volume tank means you can stock more fish?

 

[Delapool]

Good points above. Out of interest I just tried aqadvisor website for a 20g and 30g with same area and got a stocking level with exactly the same number of fish. Which I wasn't expecting, I thought the answer would be somewhere in the middle and that you could also stock more fish but not to 45%. Now if it was a building on the other hand....

 

[NoNitrates]

I don't know if I trust the Aqua Advisor site. According to it, in a 20 long with AC 50 filter, you can have 25 Cardinal tetras, OR 25 Bleeding Hearts, OR 60 Glowlight Tetras to put the stocking level to about 100%. That just seems like too many. And I changed the height dimension from 12 to 18 inches, which is about the size of a 29, and exact same stocking level %.

 

[cmwalters]

From what I understand of stocking fish, length of the tank is probably the most important thing. Length allows fish to claim territories and gives them swimming room. Of course there are exceptions to every rule, for fish such as discus, angelfish, etc. I think that the 29 would give you more stability, but as far as stocking I don't think there is a huge difference.

 

[aqua_chem]

The added volume is handy for some circumstances, eg messy goldfish, who may not necessarily be appropriate for smaller volume tanks due to pollution reasons as well as space. You also should consider volume utilization by your fish. A school of cories aren't going to care if your tank is 12" or 20" tall if they've got the same amount of bottom. However, if you've got, say, Rams and gouramis, who tend to stick to the bottom and top respectively, they can get out of each other's face more in a tall tank where 'top' and 'bottom' have more meaning, as opposed to a shallower tank where the laters are essentially mushed together.


Point is, it's always more complicated than calculators or rules let on.



That being said, I can't say that I much care for 29g. They look to me like the tank equivalent of a lanky teenager: tall, skinny, and kind of awkward looking. I much prefer tanks whose width to height ratio are closer to 1, eg, 20l, 40B, etc. It's mostly an aesthetic argument beyond what the conversation has already touched on.

 

[cmwalters]

I agree that the 29s are an awkward dimension. I think the 29 makes a better reef or fowlr tank while the 20 long makes a better freshwater tank.

 

[rmiller]

If it were me, I would likely go for the 29. It may only be 9 extra gallons, but it will give you a bit more stability.

 

[NoNitrates]

I plan on keeping small Tetras-haven't decided which ones. Maybe Bleeding Heart, Cardinal, or perhaps Glowlights. I will probably just do one species. A 29 will not give them more horizontal swimming space. But it will mean having to haul more RO water from the LFS to my house. And I much prefer the longer shape of the 20L. So I'll probably do the 20L. Or I could get Ocean Aquatics here in Houston to custom make a 24L that's a few inches taller than a 20L. Then I would get a few more gallons and still have the long looking tank. It's not that expensive for a custom tank. Last week I called them about making a super long 24 that has the same footprint as a 30L. It was only going to cost $65. But I scrapped the idea because the extra stand I have is for a 20L/29.

I have some crazy ideas. like a tank 12X12X60 inches. Or 2 20H joined by a 3 inch clear pipe so the fish can swim from one tank to the other.

 

[Delapool]

I don't know if I trust the Aqua Advisor site. According to it, in a 20 long with AC 50 filter, you can have 25 Cardinal tetras, OR 25 Bleeding Hearts, OR 60 Glowlight Tetras to put the stocking level to about 100%. That just seems like too many. And I changed the height dimension from 12 to 18 inches, which is about the size of a 29, and exact same stocking level %.

Hmm, good point - I got 19 lemon tetra which also seems a lot. Drat, as up to now had been happy with the website.

 

[Old Scales]

I got a 29g and wish a thousand times I bought a 40B. I didn't think the 36" length of the 40 would fit in the space I had. Turns out I did. So many more advantages to the 40B over the 29g especially for plants and aquascaping. For the six more inched in length, it is well worth it. OS.

 

[Delapool]

I got a 29g and wish a thousand times I bought a 40B. I didn't think the 36" length of the 40 would fit in the space I had. Turns out I did. So many more advantages to the 40B over the 29g especially for plants and aquascaping. For the six more inched in length, it is well worth it. OS.

Same here, I picked out the length and then went for height (as the tank base was fixed cost and height only a small incremental cost), looked at it and thought 'nah', went for more length and then chased height again. Now that it is in, I'm happy with it but wish I had gone for more length as it would of fitted.

 

[NoNitrates]

A few days ago I was in Petsmart and saw a 20 long and picked it up. So that's what size I'll have