Really high nitrate uptake

You have a very high light intensity, you are providing CO2 to the plants, and fertilizing them, so they are going to grow very fast, consuming nutrients as they grow. I think it is normal for the nitrates to be used quickly, but 3 teaspoons a day? That does seem abnormal. Perhaps your test kit is not reliable at all?

 

At first I thought no way your uptake could be that high, but with tons of plants and no fish load, perhaps it makes complete sense.

I have the same NO3 test kit as you (API). I also calibrated mine with a 10ppm solution that I made -- orange (10ppm) was the easiest color for me to eyeball. Mine was very accurate.

I've always had a rather high critter load in my EI tanks -- heck, even in my non-CO2 tanks, I tend to get a little carried away on critter load. So, I've had no experience with unloaded tanks. Do you have any floating plants? Some of them really use up the NO3, and you may want to avoid them, if you wish to cut down on NO3 dosing. When I was having a little trouble with a non-CO2 tank's NO3 buildup, a few floating plants really seemed to knock it down.

It seems that you have a very good feel for what is going on in your tank, even without the test kit. Sounds like things are going very well.

 

If your test is reading 0 with the API kit. I would suspect one thing. The second reagent tends to solidify to the bottom of the bottle. You can knock the bottle on a hard surface and try and break it up, then make sure you vigorously shake the bottle for at least two minutes. Also make sure you shake the final test solution for 30 seconds.

API is probably the worst for nitrate, I would rather use a test strip than API's solutions. If you must have a hobbyiest based test kit for nitrate Salifert is probably the best.

 

I took this info from another forum that asked the following companies the shelf life question so maybe useful in reference to this thread. these are the figures that the actual companies returned so they may be true or they may be a little ambitious. Who knows but its a start:

Aquarium Pharmaceuticals:
Test Solutions Shelf Life from bottling date
Wide Range pH Test Solution 3 years
Ammonia Test Solution #1 3 years
Ammonia Test Solution #2 3 years
High Range pH Indicator Solution (m-Cresol Purple) 3 years
Nitrate Test Solution #1 3 years
Nitrate Test Solution #2 3 years
GH Test Solution 3 years
KH Test Solution 4 years
Nitrite Test Solution 4 years
Fresh Water Ammonia Test Solution (Nessler) 5 years
Fresh Water pH Indicator Solution 5 years
High Range pH Indicator Solution (Cresol Red) 5 years
Salt Level Test Solution #1 5 years
Salt Level Test Solution #2 5 years


To determine bottling date check the lot # on the reagent bottle. The last 4 digits are the month and year of bottling.

Example: 33A1201 would = a bottling date of December 2001.




Hagen:

All of our test kits have a shelf life of four years. Each package is marked with an expiration date. Please reply if you have any further questions.




Tetra:

The kits have a five-year shelf life. Once you open them you should discard them after a year.

I would assume that as most of these kits will use the same ingredients that as AP states different shelf lives that the other 2 are giving a 'answer and get rid' statement rather than the actual facts!!!

Hope this helps
AC

 

Ask yourself why this might happen now.

You have a liquid solution with two parts internally. Is that reagent dependant on a thorough mixing during each use. So if you don't mix well enough each time is the solution out of balance (the two parts are no longer in balace). This would make sense to me, if this is incase problematic, not 100% sure on the importance of the two parts having to be perfectly mixed each use. If this is the case. It would only take one bad shaking of the reagent and from then on the bottle is a waste.


If your dosing EI and have decent light (which it appears you do), I would suspect CO2 is your problem. Is the filter clean? How is your circulation. I can tell you from my own personal battles 9 times out of 10 its turned out to be CO2.

I've found that adding more CO2 with added surface agitation (O2) has really improved things for myself. Often I think we get in a thought process that to get better CO2 we should limit outgassing. When we should be improving O2 while adding CO2.

Maybe Tom can chime in on if the bacteria are O2 sensitive to the point that by adding more CO2 without adequate O2 they fail to thrive, and what that relationship might be.

 

After water changes that isn't plants pearling!!! After water changes you are putting lots of O into the tank and it naturally gets trapped under leaves. Most tanks have unbelievable amounts of bubbles after water changes.

AC