New setup for convict cichlids

Hello all
I'm starting new project to move 5 pairs of convict cichlids + 6 young ones to a bigger tank. Tank will be 4ft long - thats for sure - width and length between 15x12 and 18x18. In my current fish tank (which is 54L ...i know ) i have black JBL Sansibar Gravel with grain size: 0.1 - 0.4 mm. After when decision was taken about upgrading to bigger tank i got a JBL crystlprofi e901 as a starting point. This filter is atm running with 54l tank to develop nitrifying bacteria in it which in not distance future will help me to start smoothly new tank (dont know yet how i'm gonna move fish from small to big tank coz i have only small internal filter as extra). I am planning to paint back of the new aquarium in black. Trying to think about some interesting setup of colors - i know that convict cichlids don't like very bright gravel (initialy i wanted coral gravel but due to influence on Ph i have to rethink about it). Light source I'm planing to use is t5 2x54w. So = black background + what color of gravel + what color of rocks will look interesting? I would like to keep water as clear as possible (in current aquarium there is lots of small particles flying around due to overstocked tank or the fact that convicts like to dig) and i dont know if it gonna be good choice to use black Sansibar gravel or maybe stick with something that have bigger grain. I know this post is bit chaotic but i want to do my best and gather as much information and advices as i can. I will appreciate any suggestions or interesting ideas You might have.
Thanks

Only suggestion I have is to start the new tank with Organic Aqua, its instand start up, just add water, fish and food. Seahorse stocks it. Im running a 1300l tank on it for 3yrs now.

Thx for a tip but from info i found Organic Aqua Start-Up Kit is for use in new or existing aquariums to start up and maintain a system for 4 weeks. After this time a Maintenance Kit is used every 4 weeks. Is it true? I'm not a fan of "magic" solutions and even if chemistry can help with one problem it will develop other one. Is organic start can be use as a booster for a start + matured ext. filter? I'm still trying to think how to do it with my limited resources in 4 weeks cycle.

Ive never been a fan of "miricle or wonder cures" but saying that, I have used and am currently using organic agua on 2 of my tanks!
Wonderful stuff all together in my opinion!

Sorry for hijacking the thread but I'm interested to hear about the organic aqua. I saw one of the sponsors has it on special this week at half price and will hopefully have a new tank pretty soon so how does it work? Every 4 weeks you use a maintenance kit and perform 25% water change?

As for convicts mine love hiding places so I have terracotta pots in the tank. Some on the side and some upside down with a entrance hole. Also they love coconut caves, I made some for 75 cent which was the cost of a coconut.

I've had them in my tank with a lot of pieces of mopani and bogwood with hiding places. I've used Dorset pea gravel and it does just fine. I think know they like the larger gravel as they can grab it with there mouth and move it. If you have a look at the for sale section there is a pic of the way I have my tank with convicts in it to give you an idea of what setup I have. I'm sure most people will recommend rock but I just don't really like the look of it. Each to there own!

Dont know how it works but it does exactly what it says on the tin. with my big tank I would be changing 300l weekly, using OA its every 4to5 weeks.

Id say to fully understand exactly how OA works, youd want to have a chemistry degree

All I can work out is your introducing a fprm of live bacteria and food for said bacteria to live on....

Which craft happens

And your fish are safe

Job done