It's a 20gal. I dosed a 1/4 tsp last night and my nitrates are still the same. I'll wait tonight and dose a 1/2 tsp tomorrow, which is what the graph gave me, but I just wanted to be safe. And I already dose Nitrogen, Phosphorous, Potassium and trace elements. I also dose an API product which has iron and potassium sulfate. It was the only iron product I could get at my LFS....very slim pickings. As far as Co2 goes, my DIY makes 1/2 bubble per second at a surprisingly steady pace.
I appreciate you helping me out though! We will see how this goes I guess...
Oh and why low doses? I do weekly water changes, and have read it's not bad to have too many nutrients in the water....but there are so many conflicting arguments out there! Just curious what your reasoning is
Using only one macronutrient or too high a level of macronutrients/micronutrients is an invitation to all kinds of algae to start growing, given sufficient light if I'm not mistaken. If you don't have light and CO2 at the level that the amount of ferts is enough for, the extra won't be doing you any good. Most low light low tech tanks don't use additional ferts. CO2 is a little better, glad you have a good steady level. Replace it before it runs out - unstability in CO2 is also a big invitation to algae.
Low doses, because you're not high light and compressed CO2, are all that is needed for maximum plant growth even if your 20 is packed full of well-growing plants. And I'm glad to share whatever I have picked up in the last 14 months.