23/18=1.3 watts per gallon. Not a lot of light but I think with some ferts you should be ok. I'd be inclined to see how these little guys do and then when you're satisfied they're going to live, add some more (They look a little lonely!) Give it a month or so and see how they are doing.
Edit: I have a feeling the two darker green plants are non-aquatic. I could be wrong and hopefully someone can say otherwise
I am not sure what the other 2 plants are to be honest.
Fert i have never heard of it. am really getting into the plant side of things bought some new plants for my other tank today and extra bogwood. could u recommend any good hardy plants i could buy to attach to my bogwood as would love to try it
Fert = me being lazy and not typing fertiliser Off the shelf products work well such as Tropica Plant Nutrition+ (note the plus symbol, there is a version without the plus symbol which is for something else). Seachem Flourish is another.
Nice looking tanks. Plants for attaching to bogwood include Java ferns (several varieties), Java moss and other mosses and Anubias Barteri (the "Nana" variety is most common, often just called Anubias "Nana").
Thanks Its a bit of a mess at the moment. Full of fast growing plants to stave off any algae growth (working at the moment!) I'm going to re-scape it all in the next month or so into something that looks a lot nicer Need to get some nice bits of wood and decor! Fish seem happy though! They like the "jungle" look