What Is The Best Nitrate Concentration For Plants?

[snazy]

Yeah can't say I've heard that ratio before as correct level, i read a minimum of 1:10 at least.

Same if there's a disbalance between the nitrAtes and phosphates which I think should be in 10:1 or even 20:1 nitrate to phosphate level.

That's what I said, 10:1 minimum. So if the OP wants to keep this ration but decrease nitrAtes, he's to go down from 3ppm phosphate in order to dicrease nitrAtes levels.

 

[mark4785]

Someone may say differently but your phosphate levels, although still ok, are a bit too high. Maybe that's why lowering the nitrAte has caused algae. As already mentioned, the most common, ideal nitrAte level is about 20ppm. That would give you max 2ppm phosphate allowance and even 1ppm should be plenty enough for plant growth?

I haven't lowered the nitrate level yet and there isn't any algae (I'm still waiting on the nitrate reading to drop below 40 ppm by itself). Are you referring to when my nitrate levels were low due to never having used nitrate fertiliser?

 

[snazy]

No, I was referring to phosphate to nitrAte ratio which ideally should be minimum 1:10. Currently 3ppm phosphate would limit you to no less than 30ppm nitrAte at any time in order to avoid algae issues based on that research. If you decide to test and lower the nitrAte to 20ppm, then 2ppm phosphate the most needs to be maintained.

 

[mark4785]

I'm just posting a quickly reply to indicate that I've reduced my nitrate level down to 28 ppm (from approximately 45 ppm). I haven't tested the phosphate yet; the API phosphate kit that I have for this isn't unequivocal in providing me with a definitive answer as many of you will be able to second guess. I know, however, based on the amount of dry phosphate salts (6 grams) that I dissolve into 250ml of water, that 10ml of phosphate added to 120 litres of water (the capacity of the aquarium) will boost the phosphate level by approximately 2ppm.

I add both phosphate and nitrate 3 times per week.
Phosphate at 2ppm x 3 = 6ppm
Nitrate at 8ppm x 3 = 24 ppm (10ml of Nitrate fluid equates to 8ppm in 120 litres of water).
+ 4 ppm (4 ppm of nitrate is perhaps to the surplus from biological processes or the effect of adding 11ml of nitrate by accident etc).

So, given the above, my phosphate to nitrate ratio will be 1:4.

I'm quite sure that the above ratio represents the chemistry of the water right now and I can say that the plants are continuing to grow quickly (including the hemanthius carpet). No signs of 'proper algae' are on the glass/plants; only brown diatoms (new tank syndrome algae) are growing in the crannies of the rocks.

So, the question is, if I maintain this ratio, will the plants AND the mikrogeophagus ramirezi be happy?