[Just40Fun]

High nitrate content from lack of water changes can cause small brown spots, developing into holes and yellowing leaves on plants??? Is that the same as overdose of Nitrate fert? or it's something different?

 

[plantbrain]

I've maintained 75 ppm for long time frames, as well as some spikes to 150ppm +, Richard Sexton had done some up to 200ppm for several weeks, no issues for fish or plants. Shrimps died at 160ppm for me(LD 50 for a 3 day exposure), not for Richard.

He thought the 200ppm was 20ppm :hihi:

Do a water change and focus on other nutrients/light/CO2 etc.
There is no need for more than 30ppm of NO3 for any plant species.

Regards,
Tom Barr

 

[Just40Fun]

Great! Glad to hear that higher nitrate content would not burn leaves with brown spots. I have some brown spots (dime size) on matured swords leaves. They are in a low tech tank with 2wpg, no CO2. Could that be a potassium deficiency?

 

[sfcallen]

I had nitrate off the scale on the simple test kit I have and the only thing that I saw was a little black edge on the swords leaves.

 

[ianiwane]

I think you may be potassium deficient. Try dosing KH2SO4

 

[mistergreen]

I had 100ppm (something like that, off the charts) of nitrate once.. The Veins on my Java ferns turned black.

And the fish tend to be skittish, and hid a lot. NH4 was less than 1ppm.