Deanna, how is it working for you so far?
Well, I have a few things going on. I’ve been at zero KH for a few months with no negligible effects. My fish are producing enough waste to support a constant nitrate level of about 25-30ppm. However, a few weeks after dropping KH to zero, my nitrates dropped suddenly to the 5 ppm level and have not moved much since then. Plants are thriving with no addition of nitrogen products. So, I assume that the plants are taking the entire nitrogenous waste stream at this point. I’m going to hold K in the 30ppm area because I believe my fish continue to ‘dose’ N products in the 25-30ppm NO3-equivalent region.
I need to pump-in about 10ppm PO4 a week to keep it in the 4-5 ppm area. Heavy micros along the lines of @Greggz
thread, but tuned more to Tropica’s ratios. I front-load everything after the weekly water change, except micros and iron (DTPA). Don’t want to go below 3 dGH due to fish considerations.
Simultaneously with the elimination of bicarbonates, I pushed pH below 6 with the intention of stalling the BB (along with lack of bicarbonates for the BB). Throughout all of this, for about a year now, no bio-media in my filter, just mechanical filtration (cleaned weekly).
I did get a noticeable kick in growth and GSA reduction over the last few weeks when I introduced a new CO2 diffusion approach (posted elsewhere) and abandoned my Griggs-style reactor. This created a further drop in my pH down to about 5.4. Obviously, due to increased CO2, but the fish show no sign of difficulty …unlike other attempts to lower pH via the reactor.
I think there are many ways to approach success, as is apparent with so many successful tanks (according to the proud pictures, anyway). I prefer working toward a minimal intervention status. Unfortunately, I like high light throughout the day (~80-90 PAR at the substrate, 12 hours/day), which does require intervention to keep algae subdued. So, I like what’s going on right now, but I’ll probably keep experimenting.