[ray-the-pilot]

Here’s a question for all you plant guru’s?

Ok in terms of N as NO3-, I add 7 ppm per week as a dose and take out 20% of my water.
So after one week (assuming no plant uptake) I have:
(0 + 7 )* .8 = 5.6 ppm
After two weeks I have:
(5.6 + 7)*.8 = 10.08 ppm
After three weeks I have:
(10.08 + 7) * .8 = 13.66 ppm
After a while my tank will reach equilibrium at 28 ppm:
(28 + 7) * .8 = 28 ppm

In actual fact after doing this for a long time in a very heavily planted tank, my tank water reaches equilibrium at about 18 ppm. (I am using a calibrated test that has a precision of better than +/- 1 ppm). This means that my plants are only taking out about 2.5 ppm of nitrate nitrogen per week:

(18 + 7-2.5)*.8 = 18 ppm

OK now my plants are growing gagonza fast almost doubling in a week! Why do I want to up my NO3-?

 

[jasonpatterson]

If your plants are growing well and you're not having problems with algae, I don't see why you should change anything you're doing personally. Who says you should change your nitrates?

 

[Dempsey]

If your plants are growing well and you're not having problems with algae, I don't see why you should change anything you're doing personally. Who says you should change your nitrates?

+1

Why change anything if it's working for you? If you actually know what your plant uptake is and know that you have plenty of N, why would you add more??? Esp, when you are taking the time to figure it out. You would just be wasting it. It sure wouldn't hurt anything by adding more though.

 

[ray-the-pilot]

+1

It sure wouldn't hurt anything by adding more though.

I'm actually interested in trying this out. I can up KPN together to a new equilibrium or just N. What do you think?

 

[Dempsey]

I'm actually interested in trying this out. I can up KPN together to a new equilibrium or just N. What do you think?

I'm not sure what your goal is or what you would like to find out. So, It's hard to answer that question with just one answer.

If you would like to just test things yourself and see what happens if you increase this, or that, I would say go for it.

One thing to keep in mind though is Liebig's Law or Law of the Minimum.

I can post links if you are unfamiliar.

Either way, I would say go for it. Test everything. Try them all together, or all individually.