Project 2: 120ltr community planted

I've been a lurker on here for a while, and seem currently to be posting needy questions about my problematic first (65ltr) "Learner" planted tank (thanks guys!) But I thought I'd start a journal on the main tank this learning is geared towards. It's a 120ltr that's been home to ever increasing guppies for about three years now. I took over its care as my first tank ever about 12mths ago. I joked at the time that the fun of starting this hobby was feeling like a 10yr old geek (again ... shhh... don't tell) - all those basics of water chemistry, geology, fish and plant biology - loved it.

But maintaining water quality with my shoal of randy water rabbits has been a problem. First unpleasant lesson I had to learn was humane culling and responsible disposal - I'm still not certain enough of their health to swap/sell. (I opted for clove oil sedation, followed by alcohol, then bag-wrapped funeral) We made one attempt to add a dwarf gourami to reduce fry, but it didn't survive a virulent case of fin rot - not 100% sure why, too many variables to consider (lfs choice - found a better one since; no quarantine and hear the stock has become weak from overbreading; stress from my tank being close to max stock; endemic bacterial/fungal issues in my tank the guppies have hardened to - who knows?)

In the meantime, I started seeing all these beautiful planted tanks- and started coming up with a plan...mwahahaha

The 65Ltd is destined a) to learn about plants,b) to house my best male guppies while we decide c) how to plant and community stock the 120ltr.

Not yet sure about the females. I'm very fond of them, love the extra activity a mixed sex group, and it is nice that they reproduce and restock. It's just the 1M/2F ratio can really limit stocking given that the Fs are bigger. ( I also suspect I'm having a bad ratio issue at the moment, as I've lost three Fs to unidentifiable illness the past few months.) But then the Ms delta fins are a limitation also. I've taken a big shine to greens rasboros, for example, but foresee fin nipping trouble. But I'll post again on stocking later. For the moment, I'm at the stage of adding best males to the 65ltr while we think on it. Might swap favourite Fs into the 65ltr eventually as a breeder tank. Also looking at auction site tanks for quarantine as they come up. We'll see.

My first decision is on substrate - possibly an imminent one as it would time well with stock transfer/culling decisions over the next few weeks. I've had a mix of cheap pea and fine (dark brown) gravel in there. Last week I sifted out the pea. I was planning ( John Innes 3) soil topped with the existent fine gravel.

Anyone had problems with not planting this fully straight away? Just not fully decided on plants yet, and also need to review lighting (we'd gone under watt to control algae last time we bought new ones 12mths ago) - doing it now just seems pragmatic as I'll be doing a rare high water change anyway to clear tonic salt from the tank. I can wait though.