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post #1 of (permalink) Old 06-18-2013, 07:23 PM Thread Starter
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Join Date: Dec 2012
Location: Grand Rapids, MI
Posts: 317
Hybrid Method for Dry Ferts and Excel, no CO2?

I'm trying to wrap my head around dry fertilizers and dosing for my non-co2 injected tank. I'm considering using Excel as a source of carbon. I would not mind once-a-week fertilizer dosing and a water change every other week (if possible). Ideally, I'd like something medium maintenance, a middle-ground if you will, that won't crash if I'm gone for a long weekend or can't do a water change one week. I do not mind slower plant growth, as I am planting as densely as I can from the start and already have a scape I enjoy.

My Specs:
40 gallon breeder, moderately planted
Bioload: currently only snails, but will have fish soon
Black Diamond Blasting Grit with Pfertz root tabs
Finnex Fuegray 36" that puts out high 40s PAR according to Lowe's charts, but I have a glass top so I'm not sure how much that brings the PAR down. Do I need to lower the PAR more by raising the height or adding window screen?
Lights are on 8 hours/day
NO co2 injection
pH: 8.0
KH: 6
GH: 10

I read through all of Tom Barr's thread on his non-co2 method ( and I think I grasped most of it regarding the correlation between light levels and low co2 environments and plants adapting to low co2 environments. Unfortunately most of the follow-up talk involved the watt per gallon measurement where discussing appropriate lighting levels were involved, which I couldn't understand very well because I have LEDs measured in PAR. So I'm not sure if my lighting is on par (lol, par pun) or too high with my proposed regime.

I was originally going to take an EI approach, but Tom's points on water changes -> introducing small amounts of co2 temporarily -> fooling plants into thinking there is co2 available and not adapting for low co2 environments -> algae adapts faster as co2 levels drop back down = algae bloom… kinda changed my perspective on whether EI dosing was suitable for my tank since weekly water changes and no co2 = algae problems. As I was reading, I was drawn to the non-co2 method but hesitant and nervous about going months and months between water changes. Toward the end, Tom Barr mentioned a Hybrid Method ( that uses Excel instead of co2 injection, but doesn't overdose as much as EI would. This perked my interest… weekly or bi-weekly fert dosing with more forgivable water changes or the option of going longer between water changes? But I am not using a dry start method and am unsure if I would eventually wean the tank off of Excel and water changes altogether like he discusses.

So, my questions:

Does the proposed dosing amounts and schedule below sound good for a tank already limited by no to low co2, but with Excel? I pulled it from Tom's non-co2 thread, where it was very briefly touched upon.
Shouldn't I be dosing potassium as well? Or is there sufficient amount in KNO3 and KH2PO4 for the low nutrient demands of a non-co2, Excel setup?
Do I have too much light for this method?
How do I know if a plant isn't doing well due to nutrient deficiency (adjustable) versus not being able to out-compete other plants for the low co2 levels (plant incompatibility)?
Am I even following the logic of this hybrid method, or am I hoping for something unrealistic?

Proposed Dosing:
Dose 1/8 teaspoon Potassium nitrate (KNO3) 1-2x a week
Dose 1/16 teaspoon Monopotassium phosphate (KH2PO4) 1-2x a week
Dose Traces, 4mls 2x a week (I’ll need to translate this in to CSM+B)
50% weekly water change starting out, slowly go longer between
Dose 1.5-2x the rec dosing for Excel

I understand one of the best ways to determine nutrient uptake and what the plants are lacking is by observing the plants and fish. Well, my plants are already exhibiting some symptoms after a week of being in my tank (with only root tabs). My ludwigia repens x arcuata has brown pinholes that I understand is a potassium deficiency. My dwarf sag and hygro have some yellowing and melting at the tips that I understand may be early signs of nitrogen deficiency. It's also possible that some melting is due to adjusting to new water parameters? I want to order dry ferts so I can keep my plant biomass healthy and stay within a preventative course of action. My tank is only 3 weeks old, just finished cycling, and waiting on a larger bioload to be introduced, but I currently haven't had any algae issues (yay). I'm sure introducing fish plus time can throw my good luck off, so I'm trying to give myself the best starting point with dosing.

Any help is appreciative! Thanks for reading my novel.
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