Andrew, no offence, but the flaming comes from all talk no show. Honestly if you want the flaming to stop, severely slow down on your posts... ask relevant questions. And don't post any threads about stock or the tank until you have started building. Pics are an instant key to shut flamers up. So just slow down bud. I have been where your at. You shouldn't worry about your stock at all right now. Worry about supplies, construction, pumps, filtration, plumbing, money. Once its built, don't post a thread saying, "just filled my 600 gallon tank, what should I put in it?" Think things through. Take it one step at a time, that is how you make friends here, instead of watching the movie before the script is written, so to speak.
And to be relevant to your topic, yes there are different species of cichla, but the difference isn't very noticeable to Joe blow or miss Sally. Size is very similar in them all. All of these cichal can reach 18-20" no problem.
So honestly, to save stress, and what little respect people have for you on this sight. Lay low on the tank till you start building... post a build thread. Then filtration, then stocking. And for the time being, talk about the fish you do have, and the tank that is running. Maybe reach out, get a few other 30's, 55's, maybe even a 75 or 125... experiment, you might learn something, start favoring some other fish verse cichlids. Experience is the greatest teacher. And know I'm not attacking you. Trying to help you!!
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