Potassium deficiency?

[whatsgoodm8]

Hey everyone
Alright so I recently set up a nano tank a few weeks ago and the plants have been growing nicely. Built in LEDs, sand, no CO2 or Excel, Flourish Tabs added 2 days ago and just bought some Tetra PlantaMin. I'm getting a new leaf from every plant every 5-7 days, however some are a lighter shade of green than the old leaves and the new growth on my cabomba that I added last week looks a little yellow. I looked into it and it looked like either potassium and/or iron deficiency (I read that without potassium, plants can't absorb iron properly) so I went and bought some Tetra PlantaMin because on the bottle it says "Rich in Iron, potassium, manganese and other trace elements" so I thought it would be appropriate. A few old leaves have been turning yellow then brown on a couple plants, so it sounds like it's probably potassium that's lacking, but then I read about nitrogen deficiency and it said the same stuff "in the case of a nitrogen deficiency, new leaves will look pale...". So I did a half dose of the Tetra fertiliser. Do y'all think it's a potassium or iron deficiency? Or could it be low nitrates because the root tabs and this fertiliser don't contain nitrates and phosphates. Should I just wait a week to see how the new growth? I'll try to attach photos of an old leaf that's dying and another one on the new growth of my cabomba. I just turned on the lights so my cabomba is still closed at the tip.
Thank you in advance.

 

[Bert2oo1]

Hey everyone
Alright so I recently set up a nano tank a few weeks ago and the plants have been growing nicely. Built in LEDs, sand, no CO2 or Excel, Flourish Tabs added 2 days ago and just bought some Tetra PlantaMin. I'm getting a new leaf from every plant every 5-7 days, however some are a lighter shade of green than the old leaves and the new growth on my cabomba that I added last week looks a little yellow. I looked into it and it looked like either potassium and/or iron deficiency (I read that without potassium, plants can't absorb iron properly) so I went and bought some Tetra PlantaMin because on the bottle it says "Rich in Iron, potassium, manganese and other trace elements" so I thought it would be appropriate. A few old leaves have been turning yellow then brown on a couple plants, so it sounds like it's probably potassium that's lacking, but then I read about nitrogen deficiency and it said the same stuff "in the case of a nitrogen deficiency, new leaves will look pale...". So I did a half dose of the Tetra fertiliser. Do y'all think it's a potassium or iron deficiency? Or could it be low nitrates because the root tabs and this fertiliser don't contain nitrates and phosphates. Should I just wait a week to see how the new growth? I'll try to attach photos of an old leaf that's dying and another one on the new growth of my cabomba. I just turned on the lights so my cabomba is still closed at the tip.
Thank you in advance.View attachment 297547View attachment 297548View attachment 297549

I'd say it's more likely nitrogen If your not dosing nitrogen. Nitrogen is the main nutrient for plants. I'd be dosing or versions of:
Flourish
Flourish excel
Flourish trace
Flourish iron.

Don't be scared to up your dosage. Excess nutrients WONT cause algae. All nutrients can be dosed to very high levels before they have bad effects in a tank.

 

[flchamp89]

I'd say it's more likely nitrogen If your not dosing nitrogen. Nitrogen is the main nutrient for plants. I'd be dosing or versions of:
Flourish
Flourish excel
Flourish trace
Flourish iron.

Don't be scared to up your dosage. Excess nutrients WONT cause algae. All nutrients can be dosed to very high levels before they have bad effects in a tank.

Hey...sounds like my program ...get seachem potassium too

 

[whatsgoodm8]

Alright thank you for the replies