That tank had DIY CO2.
There was no Glut dosing back then, maybe in 6-8 years later....then we saw SeaChem Excel come around.
I dosed about 5ppm 2-3x a week of NO3 as KNO3, but I also fed my fish well.
PO4 came from the tap, at 1.1 ppm of PO4.
I did 50-70% weekly water changes.
Sometimes 2x a week.
Traces I also added more than anyone else, maybe 5X the typical advanced hobbyist. Co2....I added 2-3x as much as the going advice at the time. I dose a bit more P and N these days, but it presents no issues. Some claim it does(but cannot support this claim)...if so, I would also have to see those issues myself, and having done it for many years on many tanks, different set ups etc...........and with nearly 400 species of the hardest pickiest plants in the hobby.
It does not say why they had issues, only that independent of other factors, the nutrients when non limiting play no such role in poor horticultural results. Simply because "so and so" had issues....does not imply that their claim is valid. 1001 ways to screw something up, and only a few to get something right. At least I know from experience what the issue is not.
The DIY CO2 was a headache and I learned a great deal about CO2 using this and made all sorts of devices to dissolve CO2 well while being able to vent off the DIY CO2 at night. This tank also has an overflow and Wet/dry filter, might like my tanks today. A few things have changed: sediment, tank itself went rimmless, better lights, better gardening on my own part, better CO2 and gas tanks.........etc.