[Ukelay1]

I'm starting to see some deficiency in my staurogyne repens but not sure if it's nitrate deficiency, but I don't dose nitrates because I believe I have a good source of nitrates from my fish stock.

I test with api so I might be getting false readings, should I dose potassium nitrate anyway just incase my test kit is incorrect?

The deficiency looks like the leaves on one of my staurgyne is melting and turning brown from the tip toward the base. Not sure how to post pics on here.

 

[quiquik]

Could be a number of different things going on. Are the plants new, they could be adjusting to your tanks parameters. Have you thought about calibrating your test kit? There is a thread on this forum that gives details on how to do it, can't remember who it was that posted it. I've calibrated my API Nitrate kit and try to keep my nitrates around 20-30 ppm. I have a decent load in my 50gal. with 32 tetras and corys so when I dose KNO3 I adjust it according to the uptake that my plants use and how I feed during the week. So once a week I test to see how it's going and go from there.

 

[Ukelay1]

Okay I'll take a look at that. There not newly added, I have had them for a few weeks and they grew amazing, I've trimmed them and replanted them but the old growth is browning a bit, I'll try calibrating my test kit and go from there thanks. It seems to always says my nitrates are between 20-40ppm on this tank. I check every Sunday before my 50% water change

 

[Hoppy]

If you have more than 20-40 ppm of nitrate in your water it will not harm the fish. You could double that and it isn't likely to harm the fish. So, why not add some nitrate and watch the plants to see if that helps? Just remember, if the plants do grow faster you may then be short on phosphorous and potassium. If you just follow the dosing tables in http://www.plantedtank.net/forums/11-fertilizers-water-parameters/21944-_dosing-regimes_.html you shouldn't have to worry about this.

 

[Ukelay1]

If you have more than 20-40 ppm of nitrate in your water it will not harm the fish. You could double that and it isn't likely to harm the fish. So, why not add some nitrate and watch the plants to see if that helps? Just remember, if the plants do grow faster you may then be short on phosphorous and potassium. If you just follow the dosing tables in http://www.plantedtank.net/forums/11-fertilizers-water-parameters/21944-_dosing-regimes_.html you shouldn't have to worry about this.

I've got some kno3 on order which hopefully arrives next week. I'll start dosing small amounts of that and I've been dosing seachem liquid ferts, measuring my dosing from there recommended ppm of each feet.