Can Plant ferts kill fish?

[cabezon]

In the short time that I have been using Flourish Excel in my 55 gal, I have lost a bala shark and two panda corys. I looked in my 10 gal and one of my guppies is laying on the bottom, looking sad. The plants look great. I was just commenting to myself what a beautiful little community I have and now a few deaths have me concerned.

I checked with a strip, and both tanks are good for nitrate and nitrite. I did a 50% water change as soon as I saw the sick fish. I will hope for the best, but i have yet to see a sick fish get better.

 

[JDogg]

anything can be poisonous in high ammounts, but as long as you are not overdosing then i do not think it is the excel...

 

[Jchillin]

Are you dosing any other ferts such as KNO3 or flourish nitrogen?

 

[jsoong]

As long as it is not excessive (like 100 ppm of NO3), plant ferts are pretty innocuous. The only thing that might be a problem is if you use certain land plant ferts that contains ammonia.

Excel can be overdosed at 3-4x recommended at least in the short term. However, there were a couple threads in the plants forum about people killing their fish with extreme levels of Excel (but that is with something like a 20-30x overdose).

 

[cabezon]

Are you dosing any other ferts such as KNO3 or flourish nitrogen?

Leaf zone with K20

I am following the dosage recommendations, and only dosing before I turn on the lights. I am hoping it was just coincidence as everything seems OK now. My plants are growing a lot faster now.

My guppy has gone missing though, and the other one is swimming in all levels, it looks like he's looking for his friend