my 20g Set-up plus stocking

I think I posted about my 20g, but can't find the post. But I had the tank running for 2 months now and no issues. It's lightly planted, wanting to add some more plants for background and maybe for floating plants as well.

Here's what I'm running on the tank:
Marineland 100 Penguin Bio-wheel (from my old 10g)
Aquoen Quitflow 30 (don't like it as much)
T8 20" bulb 18k, growing my medium light plants very well. I have shots coming from my one Sword.
100w heater

I use sand for the substrate. Natural river rocks and driftwood with Moss.

As for my stocking for this tank:
Kribensis Pair, Already have fry. Only had these guys for 2 weeks now.
10 Harlequin Rasboras, may add a few more.
4 Otos, Kribs leave them alone.
1 hillstream Loach I never been able to catch to rehome, so he stayed.
1 5" Bamboo Shrimp, He's just cool looking had to have one.
1 Panda platy, rehoming him for Swordtails.

I just want to get a tall plant to cover my one intake since the other side is covered by driftwood.

Well.. my male krib killed one of my 4 otos, and beat the crud out of my female krib.. so she may die tonight.. :[ I went to petco today and well 50% off all freshwater! I got 5 more rasboras and 6 guppies 2m/4f ... all my fish are in one corner.... :[

May look into some vals... Ones that grow easy.

I am surprised how well my plants are growing. The large plant in the back right was a bulb and was about 3" tall when planted into the tank a month ago. I may look for Vals since I like them. May order some later. May rescape the whole tank and see if I can find my female Krib...