That's not a flowerhorn. Those are festae. The male was captive bred and the female was wild from Ecuador.
10x is not meant to be used for stocking. It is meant for exactly what I said, minimum tank size. It works for ANY type of fish, not just cichlids.
If you want to get into stocking, you have to look at the next progression as I also said which is surface area per fish.
Using your example:
I'll assume as 20 long for this application. 12" x 30" = 360 square inches of surface area aka living space.
This formula is minimalistic, so of course if you went with a taller tank like a 29 gallon with the same 12" x 30" dimensions, you could put more fish.
So, back to the example. 2" cardinal? 1.5" is more like it, but I'll use 2" since that's what you said.
360 sq. in. / 2 = 180 per inch of fish. That's a lot of space for one fish.
360 / 20 (2" * 10 fish) = 18 per inch of fish. Much smaller space for each fish isn't it, but not completely off base for stocking.
If you use this formula and start getting close to 0 or even negative numbers then it's probably a good indication that you're overstocking.
Which is why my formula of 48x18=864 / 9" = 96% accurate in tank size for that fish is absolutely correct. You can do 864 / 36" = 24% accurate in tank size for 4 9" fish and see that the lower the percentage the less margin for error you have (filter failure, overfeeding, aggression, and so forth).
You can go even farther with this and start off with the lowest tank height and go up from there. i.e. 48x18
21" height 75 gal = 18144 cubic inches / 36" of fish = 504 cubic inches per fish
25" height 90 gal = 21600 cubic inches / 36" of fish = 600 cubic inches per fish
30" height 110 gal = 25920 cubic inches / 36" of fish = 720 cubic inches per fish
This gives an additional guide to use. You have to deduct for decorations and gravel of course.
10x is not meant to be used for stocking. It is meant for exactly what I said, minimum tank size. It works for ANY type of fish, not just cichlids.
If you want to get into stocking, you have to look at the next progression as I also said which is surface area per fish.
Using your example:
I'll assume as 20 long for this application. 12" x 30" = 360 square inches of surface area aka living space.
This formula is minimalistic, so of course if you went with a taller tank like a 29 gallon with the same 12" x 30" dimensions, you could put more fish.
So, back to the example. 2" cardinal? 1.5" is more like it, but I'll use 2" since that's what you said.
360 sq. in. / 2 = 180 per inch of fish. That's a lot of space for one fish.
360 / 20 (2" * 10 fish) = 18 per inch of fish. Much smaller space for each fish isn't it, but not completely off base for stocking.
If you use this formula and start getting close to 0 or even negative numbers then it's probably a good indication that you're overstocking.
Which is why my formula of 48x18=864 / 9" = 96% accurate in tank size for that fish is absolutely correct. You can do 864 / 36" = 24% accurate in tank size for 4 9" fish and see that the lower the percentage the less margin for error you have (filter failure, overfeeding, aggression, and so forth).
You can go even farther with this and start off with the lowest tank height and go up from there. i.e. 48x18
21" height 75 gal = 18144 cubic inches / 36" of fish = 504 cubic inches per fish
25" height 90 gal = 21600 cubic inches / 36" of fish = 600 cubic inches per fish
30" height 110 gal = 25920 cubic inches / 36" of fish = 720 cubic inches per fish
This gives an additional guide to use. You have to deduct for decorations and gravel of course.
