Who Gives A Fish Forums

I've come down with a bad case of discus fever and I'm itching to upgrade my setup. I'm currently running a 120 gallon tank, 4ft x 2ft x 2ft, with corner overflows. I've recently fallen in love with the idea of using a sump, and I think it'd be a fantastic addition to my new tank. While I adore the depth of my current tank, I'm craving more length - let's just say I'm looking for a bigger playground. Are there any fellow aquarists out there who are happy with a 4ft tank? I'm considering making the jump to a 6ft x 2ft x 2ft tank and I'd love to hear your thoughts on the matter.

I'm with you on the depth, easy maintenance and keeps me dry. Discus are mid to bottom dwellers, so the height isn't as crucial.

Re: Length vs width vs height

I've found that bigger isn't always better for discus tanks. Once you hit around 75 gallons, maintenance starts to get a lot tougher. Cleaning and water changes become a real chore. Neglect that, and you'll end up with unhappy discus. I've seen it firsthand - a local hobbyist has a 300-gallon tank, and it's just not manageable.

Re: Length vs width vs height

Thanks for the input guys, I think I'm good with my 120 gal.

Re: Length vs width vs height

Originally posted by D'bunk

I'm inclined to agree with FairyFish's assessment on height. And I don't entirely disagree with wilde, large tanks do have some maintenance advantages. However, it's worth noting that the greater volume allows for less frequent water changes – assuming you're not overstocking.

From my experience, larger tanks tend to be better for discus. I'd argue that length is more crucial than either horizontal or vertical depth, with vertical depth being the least important. While I wouldn't keep discus in a tank shorter than 6 feet, I understand that some people might be happy with a 4-foot tank. In my opinion, a standard 125-gallon tank is the minimum size suitable for discus.

As for the information on tank length and natural behavior, I've based my opinion on various studies and observations. Natural behavior, to me, refers to the discus' ability to swim and interact with their environment without feeling constrained. In a shorter tank, they may not be able to fully exhibit this behavior, such as schooling or exploring their surroundings.

Re: Length vs width vs height

I'm not sure what's considered natural behavior for discus anymore. I mean, most of them are bred in tanks and raised in grow-out tanks, so is that really natural? A 4'x2'x2' tank might be perfect for them, who knows. They're not exactly built for long-distance swimming, so maybe they're just happy cruising around in a smaller space. On the other hand, a bigger tank could be overwhelming, like they're constantly on the move and feeling threatened.

Re: Length vs width vs height

D'bunk, I've read your posts and I must say, they've motivated me to consider a longer tank. However, I still believe the depth of my current tank provides ample "places for the fish to go". I agree that overstocking, like in an African cichlids tank, is far from ideal. But I'd argue that a 4ft 120 gallon tank, when stocked appropriately, is still more than sufficient. I'm curious, what exactly do you mean by "natural" behavior in this context?

Re: Length vs width vs height

I've had discus in both 4 and 6 foot tanks, and to be honest, I haven't noticed a significant difference in their behavior. My experience with stocking has been a different story, though. I had 6 full-grown discus in a 75 gallon tank and it was a bit too crowded for my comfort. Similarly, 10 discus in a 125 gallon tank, all around 6-8 inches, was doable but still felt crowded. The key, I think, is not so much the depth but the surface area. In an overstocked tank, the surface area is crucial for gas exchange and oxygen levels. The more surface area, the better. I've found that the 1 fish per 10 gallon rule works, but it can look a bit crowded, especially when you're dealing with larger discus that average around 7 inches.

Re: Length vs width vs height

Thanks for the input, I'm considering a slight upgrade from my current 4x2x2 foot tank to a 6ftx 18 inchx29inch tank. Not thrilled about the height, or the fact that it's slightly narrower. D'bunk, I'd love to hear your thoughts on this.

Re: Length vs width vs height
I've got a 30" tall tank, and yeah, it can be a bit tricky reaching the bottom, but the fish seem to be just fine with it. They're using all levels of the tank, no issues there.