I set up a little planted tank in my office earlier this summer as a little work-hobby. I've had hobby aquariums as a kid (25+ years ago) and worked with fish on a large scale (research facility), so I know a bit about fish biology, but the planted tank approach and small scale is new to me. So far it's been a lot of fun!
It's a 36 liter tank that's pretty shallow (60w x 20h x 30 cm). Fluval 20 HOB. Substrate is Tropica aquarium soil (black) plus some rocks and driftwood. Sorry to say I don't know plant names, but the tank is heavily planted and has CO2 from a tank and an LED light bar, gets a bit of natural sun from a window (but shaded by a plant). I have not bothered to measure CO2 but run it around 1-2 bps. Most of the plants seem healthy and are slowly growing, and judging from bubbles are photosynthesizing/respiring actively when the lights are on.
After cycling, I added fish 2-3 at a time up to the current (high, I know) load:
6 neon tetras
1 rummy nose tetra
3 lampeye killifish
1 small pleco
1 small oto
6 red cherry shrimp
Maybe a lot for 36 liters, but I run the HOB at full speed, again have a ton of plants, do weekly ~20% changes, and use SeaChem prime with water changes + 2 more times per week.
The first challenge was a major algae outbreak. I lost some plants, but think I've solved it with Seachem Flourish Excel, light period shortened from 8h to 6h, a toothbrush, extra water changes, and this is when I added the shrimp and the oto).
Some challenges I have now:
Two days ago I noticed the Rummy and 2 of the tetras have ich, which I assume came in with some recent plant additions from a pet store. I've been raising the temperature to 80-85 (didn't use a heater before and kept it at ~72) and am planning on using a 1/2 dose of Nox-Ich (0.5% each NaCl and malachite green) with the lights off and carbon filter removed for 3 days.
My concerns:
Shrimp and plants. It's not practical for me to remove anyone during the treatment. I'm hoping the 1/2 dose + heat is the right approach?
Biological filter will survive this?
O2 levels... with lights off and the plants stressed, will the fish be ok? Only air will be from HOB surface agitation. Tank has a large surface area for its 20cm depth, but still.
I turned the CO2 off during this... correct?
Assuming everyone survives this, I have one more big picture question: my fish are very shy! When the lights are on they almost always hide under driftwood / plants unless feeding. Is this normal? Related to the tank being shallow? They've been in the tank 3-4 weeks. Other than the Ich, they look healthy. The shrimp seem very happy, are active, eating, and growing (I find shed skins all the time). Water quality is good, regularly dosed with Seachem Prime (and Flourish / Flourish Excel).
Anyway, thanks for reading through all these beginner problems!