Plant fertilizers safe?

[Reptileguy2727]

Do aquarium plant fertilizers pose any risk to amphibians? I use an assortment of Flourish products.

 

[Lasher]

It depends what they contain.
In any case you should use very dilute amounts only where nescassery. I prefer slow release tabs(carefully checked for any newt unfriendly chemicals) buried in the substrate. They last for about 6 months and 'feels' safer than suddenly introducing ferts to a tank.

 

[Reptileguy2727]

What should be avoided?

 

[jpmf]

I use in all my Vivs, a fertilizer that I bought especially formulated for Dartfrogs.
If it is safe for Darts It should be safe for newts and salamanders.

 

[Reptileguy2727]

In my 75 (goldfish, guppies, axolotls, lots of live plants) I have been using Flourish Tabs and the general liquid Flourish for a while now with no visible problems. I just started using Flourish Iron last night (other liquid didn't have enough).

What problems do people have when they use a bad fertilizer?
What chemicals are the ones to be avoided?