Alan79
Aquarium Advice Freak
I like the natural look so i add a lot of smallish different looking rocks to the floor of the tank to break up the substrate till it's covered in plants. I haven't quite managed to do so yet, foreground plants don't thrive for me. I would do a quick google search of each species and Care eg Neon Tetra care. Most pages will tell you if you need anything specific within your tank to keep the fish chosen happy. I am still having to research all my fish before i buy them so just see if your fish will like some caves to hide in or anything. I think some cory species might be shy so might appreciate hiding spots.
In terms of plants i would start out with a few stems that do well with low light and that will reproduce reasonably quickly like Ludwigia Repens, Pennywort, and Cabomba. I quickly went from having 5 stems of Ludwigia to having to toss some into a second tank. Pennywort grows even faster. Anubias goes well in most tanks and comes in many shapes and sizes, has cool green roots that will wrap around rocks or wood when tied down. I also love Crypts, but they do like Root tabs which can be expensive (I am trying DIY Osmocote plus tabs this week). Of my Crypts, Brown Wendtii seems to grow fairly fast compared to Lucens and Red undulata but the three Crypt types i have now are doing well. Java moss is very easy to grow too but once in your tank it can be difficult to remove and stray parts will float away and begin growing almost anywhere.
Everyone has their own preferences with plants so i would probably try and have a read of this thread which has a great list of low light plants.
Excellent List of Low Light Plants
As far as the number of fish i have in the aquarium being too high. I ran the numbers with Aquadvisor and it just tells me i need a few % more filtration (which i think plants will help with as long as i don't go way overboard). When it tells me that i stop adding and think about changing stock before i buy anything. The Tetras and Rasboras are quite small and have a low bioload. My Kuhlis will also eat almost everything that manages to sink to the floor of the aquarium so if i don't overfeed the stock number should be ok. The guppies you plan to add have a pretty high bioload for a fish of that size so they will reduce the number of fish you can stock by a bit. Maybe swapping them for something different on aquadvisor would allow you to add more fish if you wanted to go that way. Guppies are pretty though so keep them if you like them.
Sorry to get long winded.
personally, i would go with a dwarf cichlid as a centerpiece, rather than a betta. apistogramma cacatuoides is a beautiful, very easy to care for, dwarf cichlid.
