Tailoring a fert regimen
Hello everyone. I just joined this forum a few days ago and this is my first post. I've kept aquariums off and on for 20 years or so but this is the first time I really have tried to keep any mentionable amount of aquatic plants. I've successfully kept all sorts of fresh and saltwater fish and invertebrates, but my prior attempts at growing plants have more or less resulted in decaying vegetation.
For my reentry into aquarium stewardship, I dusted off my old "solid oak" stand (Remember that company?) and bought a new aquarium for it. Somehow in the last ten years or so I managed to lose the old 65 gallon tank. Im currently running a dual 40W t5 ho light fixture and have flourite for the substrate. Im not running co2 currently as I had initially intended to do a low tech set up but I've changed my mind on this and plan to install a system in the next few weeks. My tank looked wonderful for the first two months or so, but now Im getting frustrated with the amount of green spot and hair algae appearing in the tank.
In the first stages of my tank I think I had the wrong mindset as far as how to maintain the aquatic environment. I beleived that the waste from the fish, products of their respiration, and the minerals naturally present in the water and substrate would be more than adequate for healthy plant growth. After all, that's how it works in the natural world right? I'm now coming to terms with the idea that Im going to have to routinely fertilize, get another t5 fixture, and add co2 to the mix.
Right now I'm growing rotala, which appears to be rotundafolia, dwarf hair grass, red milfoil, and I have 1 each, unknown cryptocoryne and some sort of large leaved anubias. The rotala looks great and grows quickly. The hair grass grows moderately fast and looks fine, the crypt is ok, and the anubias is covered with algae. The milfoil looks horrible and the new growth on it seems bleached out somewhat.
My tanks pH is around 7, gH of the tank water is 8 degrees, and I can't detect any amount of nitrate what so ever even if I skip water changes for a week or two. This last part is what finally convinced me to start ferts.
My main questions are: With a hardness that high, should I leave out MgSO4 from my dosing, with extremely low nitrates can I add a higher level of potassium nitrate, and lastly, can the ferts be added to water during water changes and replentished that way rather than the EI method of daily dosing and changing 50% weekly? My old school way of thinking is that changing large amounts of water in a single day is stressful to the fauna.