Help with fertilizing a 75 gallon low-tech
I've had my 75 gallon setup since 8/6 and my plants aren't really growing all that much as I hoped for... I have a lot of supposed fast growing 'easy' plants. I have some tiger lotus bulbs in there that are going crazy as well as some wisteria. But I haven't noticed any growth on my Echinodorus uruguayensis just leaves slowly turning yellow and withering away. I have some italian val that hasn't grown much either. But I think the main reason is, is because I'm not fertilizing anything to the tank. I'm dosing 5ml of Excel every week but I feel like that isn't enough.
My water change schedule is 10-15 gallons every Sunday.
As it stands there are no fish but 5 Amano Shrimp and about 50 RCS. Mainly a shrimp tank for now until I can figure out the plants, then add fish.
Substrate: Eco Complete- Good 2.5-3 inches throughout
Lighting- Home Depot Diamond plate dual T8 with 2 6500k bulbs
I read up a little on EI dosing but I don't know how to calculate the numbers.
I'll upload a picture of the tank so you get what I mean.