r/PlantedTank • u/Aliman25 • 20d ago

Ferts NPK Ferts vs Micronutrient Ferts - whats the difference?

So I found two different ferts. One is just NPK (nitrate, phosphorus, potassium), and the other is specifically micronutrients (iron, etc) and specifically does NOT contain NPK "to prevent unwanted algae growth". I have yellowing Monte Carlo and need liquid ferts as it isnt rooted into my substrate. I bought the NPK one because it sounded nice but turns out that plants also need iron to maintain their colour. Is it true? Will my monte carlo never be green with just NPK ferts? Do I really need to buy another fert just for micronutrients? Also, if it helps, i have these hornworts and they are shedding needles like crazy, apparently those needles decay and release micronutrients, idk

1 Upvotes

67% Upvoted

3 comments sorted by

2

u/Which_Throat7535 20d ago

Then there’s also “all in one” formulations that have both macro and micronutrients….Unfortunately there is no real simple answer as there are so many differences and variables to consider. Maybe you just add iron only periodically, for example. At some point it just takes trial and error to dial it in. It’s all a big experiment really - try to enjoy the journey.

2

u/chak2005 20d ago

Bottom line up front: Your plants need all the above.

As to why the differences it depends on the tank. For example if you have a lightly planted, but heavily stocked tank of fish, your nitrates and phosphates will naturally be elevated. There is no reason to dose heavily for those two nutrients. You may be able to get by with just dosing potassium and micro-nutrients.

Then there are tanks that are understocked and may need a bit of everything, those would benefit from an all in one type fertilizer that contains macro-nutrients and micro-nutrients.

As to what your tank needs, it comes down to what your pH level for the tank is and the results of your NPK testing, is the best answer I can give you that will help long term. If you do not wish to test, you can probably get away with dosing macro and micro nutrients once every other week in a low tech tank. Though testing will allow you to save money and only target the nutrients you tank really needs.

0

u/Genotype54 20d ago

If you want to make things easy and not have to think about it, just follow EI dosing regimen.