Nitrate level and EI dosing

[bojon]

Hi,

I've a 75G planted tank, with pressurized CO2, and about 3WPG of lighting. I start EI dosing recently. I dose half a teaspoon of KNO3, which provide about 6ppm of Nitrate to the tank. I found that the nitrate level back to 0 the next day. The EI dosing recommends dosing macro every second day. Is it mean I am not dosing enough KNO3 to keep the nitrate level at 5ppm everyday? Or it is normal to let it back to 0ppm and wait until the next dosing.

thanks,
jon

[sdivell]

I have to dose nitrate every 3 days as the plants eat it all up

[fischkopp]

It is good that the plants take up all the nitrate. EI tends to aim for 10ppm nitrate.

That said, I would not increase the dosing based on what the test kit measures. Plants can take up some nutrients and store them for a bit. If plants suffer under nitrate deficiencies they try to transport the N from the older leaf tissue to the newer growth; as a result old leafs will turn yellow. Look out for it, increase your dosing only if your plants don't look healthy.

EI suggest to dose macros every second day so that you can dose micros in between. The reason for this is to avoid dosing phosphates and iron at the same time, because the P would bind the Fe so that it becomes unusable for plants. In the end you can decide how much you dose, every second day, twice a week, once ... I go with twice to lower maintenance.

[bojon]

oh..it is 10ppm? opsss...i think i know what to do now...thx

[fischkopp]

oh..it is 10ppm? opsss...i think i know what to do now...thx

I double checked: the mainly recommended dosage is somewhere between 5 to 10ppm. I dose more on the higher side since I do it only twice a week  Those levels are pretty much different for every tank, it all depends what grows in there.

A highly recommend to watch the plants and to increase the nitrates only if you feel they are not doing so great. Also, increase the dosing slowly over a month or so if you decide to do so.

[bojon]

thanks, in fact, yeah, my sword plants are having yellow leave, esp on the older one..so thats why i look at the nitrate so closely recently. It is just that i don't think mine is a heavily planted tank and i didn't expect the nitrate level would go down so quickly. anyway, thanks a lot.

[fischkopp]

Amazon sword take up most of their nutrients through their root system. Root tabs will work wonders. 

[dan2x38]

I do twice a week IE like Fischkopp. I dose heavier KNO3 then recommend ratio of KH2PO4. Like mentioned every tank is a different. I was getting some diatoms on a few leafs. I also use root tabs because I have some heavy root plants like swords & crypts. I did find that I only needed 1/2 a tab between the plants. When I followed the recommended dosage for the tabs I had an algae break-out twice before I figured out what was happening. The extra ferts were coming from the tabs leaching into the water column.