There's a lot of talk from a lot of knowledgeable people about fertilization when/how/how much. It's easy as a beginner to get overwhelmed, or worse, think this is just a bunch of hooey (Sorry for the language!)
Here's a story of my 55 gallon and its trials and tribulations. I'll try to keep it short...
I received an entire 55 gal setup for free from a friend and did a lot of research and learned about cycling the tank, plants, lighting, etc. I put my lessons to work, adding fertilizer, adding plants, adding fish, trimming plants... Things generally went well until we moved two years ago. The tank move went fine, but I was so busy with the move and settling in I neglected my tank. It started to go bad. First some green algae, then BGA. I cut back on fertilizer (as some have said too much fertilizer, esp Phosphate, can cause this). Added Antibiotics to knock down the BGA (which works great, BTW!) Slow growth, enter Black Brush Algae. Added algaecide and upped Excel to try to beat it back. Now adding almost no fertilizers and dazed and confused by my terrible situation. Tested Nitrates and confirmed they were very low (Too much causes algae, you know...
We took a week's vacation, leaving the tank and instructions to my parents. We came home to a Green Algae bloom in full force. I stopped fertilization, reduced photo period, increased water changes, performed frequent thorough cleansing of algae from the filter floss (I know, I know!!!), eventually did a full 3-day blackout. Tank looked better, but still hard to even see the fish. Now fish are starting to die. In great numbers, in fact.
(I know, this is a lesson in what not to do, right?)
I began reading up again on tank cycling, fertilization and reading with great interest about using the Estimative Index (EI) method of dosing. I realized with the house, I had forgotten all my best practices, made some stupid decisions and listened to some bad advice. I was doing it ALL WRONG.
So here I am: Green tank, dying fish, plants either not growing or covered in BBA or just plain dying. It's as bad as you could imagine.
A new UV sterilizer removed the Bloom in just a couple of days. I was left with cloudy water, likely the result of a bacteria bloom. Ammonia present, meaning my BB and biofilter would have to be rebuilt. But Black Brush algae is no longer growing! I started dosing following a gradually increasing EI schedule (not too much change at once!), increased photo period back to normal, began adding 1-1.5x on the Excel dosage. Frequent water changes to reduce Ammonia/Nitrite. Added many new, healthy plants. As the cloud started to clear, I increased my fish supply/bioload. Full Excel-tank-level EI dosing now. Black Brush algae is actually dying and/or disappearing from my tank walls and decorations. No signs of green algae.
In the period of really just a few weeks, my tank went from a green, cloudy fish-killing machine to a crystal clear tank with plants growing noticeably every day and fish eating voraciously and playing constantly!
What did I learn?
- Don't forget your basics.
- Fertilizer is NOT the cause of (most) algae issues
- Chemicals are a LAST resort
- The Planted Tank forum members are ROCK STARS!
This is a lesson I won't soon forget. I hope you can learn from my experience and learn to trust the natural cycle that governs our plants, fish, water. EI saved my tank. THANK YOU, TOM BARR!