I'm happy to offer what I hope will be helpful suggestions on the questions/issues you've raised. First comment, is to mention the photos of my aquaria that are under the "Aquariums" tab below my name on the left; I have maintained tanks like these for over 15 years on the simple methods I recommend, so the proof is in the photos. And by the way, at the head of this section of the forum is a series of 4 articles entitled "A Basic Approach to the Natural Planted Aquarium" that goes into more detail on various aspects of the natural (low-tech) method I use; they might offer you some background.
I have not tried it, but from what others have said and having researched the ingredient nutrients I believe Nutrafin's Plant-Gro should be good. I have used their substrate sticks, and the result was to me quite remarkable. While not all 15 mineral nutrients are in Plant-Gro, it may have sufficient of the essentials plus others that naturally enter the tank via water changes and fish food, or are made available through bacteria/organics. If you are satisfied with the growth, and assuming the light is brought into balance, fine; if not, I recommend Seachem's Flourish Comprehensive Supplement for the Planted Aquarium. It takes much less--only 2 ml in a 20g once or perhaps twice a week--so it lasts longer, and it certainly works for me and many others here. By the way, assuming you use a water conditioner than detoxifies heavy metals, do not add fertilizer the same day but wait 24 hours after a water change. Several plant micro-nutrients (iron, copper, zinc and manganese) are strictly speaking "heavy metals" and the water conditioner detoxifies these so the fert is wasted. Most conditioners only work for 24 hours or less, so the next day should be OK.
Plants will grow very well in plain gravel; and root tabs for some like the heavy feeding swords and perhaps crypts is not a bad idea. I did this myself last year for the first time, I used the Plant-Gro sticks as I mentioned above which are less expensive that Flourish tabs and the improved growth in the swords was very noticeable. A small-grain gravel is best on all accounts, around 1-2 mm grain size; it anchors plant roots and provides an excellent medium for bacteria as water easily passes through which is essential.
Algae eaters are fine, I have some though not for that particular reason but simply as interesting fish; but with one or two exceptions they will not touch hair algae, brush algae, and those other difficult algae types. Prevention is the best action.
On the CO2/Excel, as I mentioned previously, there is considerably more CO2 in our aquaria than many of us realize. For several months I had my 33g full of plants, daughter plants from swords, some Pennywort, floating Ceratopteris, etc., and no fish. The plants remained alive and quite lush, though obviously not as thriving as in the main fish tanks. But this surprised me, as I expected with what I thought would be no source of CO2 they might waste away. But the CO2 from bacteria plus some from the atmosphere (floating plants make use of this readily) was sufficient for more than 5 months. And even in a tank with fish, there is more CO2 from the bacteria in the substrate than from the fish. As long as the light is kept minimal, there is no need for CO2 supplementation with the vast majority of aquarium plants. And increasing the carbon via CO2 or Excel raises the balance level between light and all 17 nutrients, so without also raising all that, the carbon will have little usefulness.
Thanks again Byron, and Redchigh. Will read the 4 articles of this forum, and have made the following changes to my aqaurium care which I think will help a lot.
- (2) 13W CFLs outfitted on my hood (lighting is just as bright and much cooler, as expected)
- Moonlight goes off at night, keep it on during the day to inject more blue for the plants
- Plant fertilizer not added same day as Prime (didn't know that)
- Will get Seachem's "Flourish Comprehensive Supplement for the Planted Aquarium" and replace my Flourish Excel
From what you're saying it sounds like I probably have enough CO2 in there. I tested my water last night and it was spot on - NH3,4 = 0ppm / NO2 = 0 / pH = 7, which tells me the tank is in good balance. I just need to give my plants the right supplementation, as I would like to see them grow more now.