Nature Aquarium Going Through Difficult Times - Help!
So this is my low-tech, heavily-fertilized, heavily-stocked (plants AND fish) nature aquarium. This is my first ever tank and I've had it for about 5 months now. Its a 125 Liter (33 Gal) Juwel tank with the stock MultiLux LED lights and filter, which has a flow-rate of about 500l/hr and a turnover of 4x/hr. However, I modified the filter media to include a ton of Seachem Matrix and my tests are always perfect. Although its technically a low-tech tank, I use a carefully regimented dosing schedule, which I've attached below. I also used ADA Power Soil and ADA Amazonia II for the substrate. I do about a 35% water change every week.
For the first 4 months, it was growing beautifully and better than I ever expected given that it was low-tech. However, the last month has been particularly challenging in that I started to get a ton of glass algae. I had a small hair algae problem in the past but after adding some Amano Shrimp, that hasnt been a problem anymore. I've been scrapping my glass every 2 days or so just to keep up with the algae growth. Whats worse is that my plants seem to have taken a serious hit. Many of them have started to darken and grow brown dirt-like spots and stopped growing altogether. I've attached a couple of pictures to show you the examples. My montecarlo and weeping moss have become especially darker as well. This is my full plant list:
- Monte Carlo (Darkening and not growing)
- Weeping Moss (Was growing intensely during the first couple of months, now is struggling)
- Anubius Nana (Surprisingly struggling)
- Sagitaria Subulata (Melting)
- Staurogyne Bihar (Ok)
- Staurogyne Repens (Brown spots)
- Java Fern (Blackening)
- Cryptocoryne Costata (Brown Spots)
My stocking list (AqAdvisor stocking level: 89%):
- 13 Neon Tetras
- 13 Harlequin Rasbora
- 2 Pearl Gourami
- 4 Otocinlus
- 7 Amano Shrimp
If I'm honest, things started to really take a dive after adding the last 13 harlequins. All these fish were added incrementally over the course of this tanks existence, however these harlequins could have been the feather that broke the camels back. I've brainstormed a couple of possible reasons that could have created this problem and I'd really appreciate your feedback.
1) Tank is overstocked, need to remove some fish
2) Need to upgrade filter pump (Juwel do a 1000 l/hr filter pump that is compatible with my filter)
3) Need to start adding the macro elements Nitrogen and Phosporus
4) Need to reduce dosing altogether
5) Need to upgrade to high tech CO2 injection and lighting
I understand that its a long post but I really wanted to give you guys all the possible info you would need to break down what is happening in my tank. I added two main layout pictures of my tank. The one with the thick moss, red plants and cabomba is the older one. Its worth noting that I cut down a lot on the plants I have because many of them started to struggle quite badly and moss was covering all my pretty seriou stones!
I'd really appreciate the guidance, thanks in advance!