[punman]

My initial thought was to do a group of 20 tropheus in my 90 gallon tank and then, if I love it and am successful, free up my 180 gallon, move them from the 90, and add a second compatible group of 20 six months down the road.
Now I am wondering if I should just go for the 180 gallon now with two groups if I can find and afford two at the moment.
Any pros and cons to my dilemma?
What do you think of my numbers (assuming I am starting with 1.5 to 2 inch fish).

 

[NorthShore]

The numbers are good, and I do think any fish would do better in the 180 as compared to the 90, especially tropheus, but here's where I stumble with this question. Water changes. It is critical for growth that water changes be large and frequent. Minimum 30% weekly, ideally 50% weekly. It will be easier to do that in the 90, but you wouldn't be able to have 2 groups.

Single groups do better for spawning. With 2 groups, one will typically outbreed the other.

If you're not concerned with one group dominating the other, go for the 180. :thumb: :dancing:

 

[wild wally one]

I would suggest to make two groups. I would keep your red chimbas in the 180!!!! By doing so, will make these fish thrive and breed for you like there is no tomorrow!!!! Use lots of rock work in combination of white/black sand as your substrate. Carribean sea makes this product. I got mines at Mops.ca. I am now keeping three diffrent breeds of trops myself and they are in their own 130 gallon tanks. The trops that I'm keeping: T. Illanghi(26) T. Orange Flame Bembas(25) T. Halembe Duboisi(29) Working on getting more tanks for two more breeds of trops!!!! Thats if the lawyer agrees with this decision!!!!! LOL!!! The bigger the aquqrium, the easier it is to manage the water. I would do a 50% water change weekly. Conditioning my water with Prime everytime the water is changed. This stuff is great and very easy to use. One capful treats 50 gallons of water. In this hobby (keeping trops) gets crazy when it never stops!!!!! Will at least it keeps me out of trouble!!!! Have a great time with the hobby and good luck to ya!!!!! Have fun!!!!

 

[wild wally one]

I would suggest to make two groups. I would keep your red chimbas in the 180!!!! By doing so, will make these fish thrive and breed for you like there is no tomorrow!!!! Use lots of rock work in combination of white/black sand as your substrate. Carribean sea makes this product. I got mines at Mops.ca. I am now keeping three diffrent breeds of trops myself and they are in their own 130 gallon tanks. The trops that I'm keeping: T. Illanghi(26) T. Orange Flame Bembas(25) T. Halembe Duboisi(29) Working on getting more tanks for two more breeds of trops!!!! Thats if the lawyer agrees with this decision!!!!! LOL!!! The bigger the aquqrium, the easier it is to manage the water. I would do a 50% water change weekly. Conditioning my water with Prime everytime the water is changed. This stuff is great and very easy to use. One capful treats 50 gallons of water. In this hobby (keeping trops) gets crazy when it never stops!!!!! Will at least it keeps me out of trouble!!!! Have a great time with the hobby and good luck to ya!!!!! Have fun!!!!