I had a question about this. I'm trying to develop a dosing plan for my tank, and I'm grappling with a dose that is enough so that it doesn't go to zero between doses but isn't so much that it causes GDA.
Dennis Wong called GDA the "Aquascaper's Algae", meaning it's the one algae that can still show up (particularly on the glass) when you've balanced your tank's dosing requirements, especially in high-NO3 environments.
I currently scrape algae with my magnetic scraper before each weekly waterchange. I can sometimes go 1.5 or 2 weeks without it, but the glass gets really green.
The easiest way to do this is to split up front loading doses, particularly for KNO3. For example, If my goal is
26-6-35 as the weekly front-loading, I could dose it all on Sunday and likely get some GDA on the glass by the end of the week. Or, I could do
13-3-17 on Sunday, and on Wednesday, for twice-weekly dosing. Levels would technically be more stable and less likely to produce GDA. I don't do this because I'm lazy -- dosing once a week is so damn easy. I don't have any algae -- I mean ANY algae -- in my tank right now with very little maintenance, and very high nutrient levels. The only algae I currently get is GDA on the glass... my bristlenose plecos take care of any GDA on my hardscape.
As the OP, only I can determine if there was a hijack!!!
Good, let's keep it going!
I feel like here though, you mean "reach zero" for an extended time and not just the hours to day or so before you dose again.
How long is an extended time? a few days, a few hours? Some plants who have fast metabolisms could either benefit or suffer under limited conditions. I've read from
@GreggZ and
@Burr740 stores of how plants can bounce-back within hours or days from a nutrient-limited scenario once they started dosing again. If you run out of NO3 by 3pm every day, you're still causing a nutrient-deficient scenario, even if it's not as bad as it could be.
Not too long ago in my experiment tank, I tried "precise daily dosing" via my Chihiros Auto Dosers as an attempt to eliminate GDA from my system entirely.
The goal was to keep levels at essentially 1/7th of my weekly front-loading, to keep GDA off the glass, to keep the water column lean, and only supply what was necessary each day. Seemed like a good idea, especially since I was genuinely feeling bored with the success of EI dosing.
It was SO much harder than general "EI" dosing for me. I found that it was way harder to get daily readings on leaner nutrient levels, as the kits aren't as accurate. Is it 5ppm, 2ppm, 0.1ppm?
I had to take readings 2 or 3 days in a row at the exact same time of day to get a visual for trends, because the daily uptake reached near zero each day. VERY quickly I got multiple types of algae; GSA on my older leaves from lack of
PO4, pinholes all over my S Repens leaves from lack of
K. I found I wasn't very "in-tune" with my tank's health, since the weekly maintenance wasn't as required this time around.
Things like K2SO4 solubility being so low, nutrient accumulation, trusting the auto-dosers to perform accurately every day...
I was dosing about 3.5ppm NO3 per day (26ppm per week) and still got some GDA on the glass. Not as bad as when I front-load one large dose, but it was still present. However, the plants took a serious decline in health and the algae killed me.
I decided: It might be possible to configure some kind of daily dose that provides all the elements our plants need (essentially PPS-Pro dosing concept), but to keep it non-limiting, you have to dose more than what the plants consume, which eventually requires a water change to balance it out... which is already 50% of what the EI method requires. In my mind, all roads lead back to Leibig's law and nonlimiting environments. It's a
requirement to grow plants and keep algae at bay, so that should be my priority.
I guess I'd rather have to scrape some mild GDA off my glass once a week for my whole lifetime, while having incredible plant health, growth, and appearance, than constantly fiddle with daily dosing after the experience I just had for the last month
I do theorize that if daily dosing is 7/7 days, and front loading is 1/7 days, the sweet spot is the average of the two: two doses, one up front, and one halfway through the week, to prevent limiting environments without getting too much GDA on the glass.
I'd say whatever you do, keep good records/photos and make sure to share here on Scapecrunch. The discussion is so helpful for so many, I think!
