Nitrogen fertilizer in puffer tank

[Minipuff]

I have a heavily planted 112-litre tank with 6 dwarf puffers and 4 amano shrimp. I do 50 % water changes every week, and I monitor water parameters with liquid test kits. The plants are not growing all too well, and it seems to be due to almost zero nitrates all the time. It appears that the bio-load from my fish is not enough to keep nitrates up (don't know about phospahtes, waiting for the test kit). Did not expect that problem in a puffer tank...

So, I just bought some liquid fertilizer, and then I discover that it contains both nitrate AND ammonia (and also copper, among other elements). Will this ammonia (and possible copper) harm my puffers?? It was claimed that the fertilizer is suitable for all fish as well as shrimp and snails. What do you think - okay or not?

[Iliveinazoo]

Presumably you mean it has ammonium nitrate not strictly ammonia? Copper is required in tiny doses.
Most of the fertilizer that you are dosing will be water so the actual amount of each 'ingredient' in each dose will be very small. A heavily planted tank will always need extra ferts, you can slightly overdose as well as long as you keep up with your water changes to remove any excess, just be more careful when overdosing with ferts that contains ammonium nitrate compared to potassium nitrate.

[Minipuff]

I don't know which compounds it contains, the label only says "contains nitrate, ammonium...". The name of the product is Tropica plant growth specialized fertilizer. But I suppose it is safe to use, then. I'll start by underdosing to be on the safe side, and increase the dose gradually.

[Iliveinazoo]

I don't know which compounds it contains, the label only says "contains nitrate, ammonium...". The name of the product is Tropica plant growth specialized fertilizer. But I suppose it is safe to use, then. I'll start by underdosing to be on the safe side, and increase the dose gradually.

like many other manufacturers Tropica specialised contains ammonium nitrate. I think that it would sensible to do as you say, start with the recommended amount on the bottle and if you see no real improvements over the course of a week or two then follow the pattern of slowly increasing the dosage and monitor. Depending on your light intensity you might want to consider a carbon source be it liquid carbon or CO2.

[scpion]

The kind of substrate plays a big part as well. Many substrate (sand/gravel etc) contain close to no nutrients at all if u are using it alone. Most planted tank hobbyist use a layer of base fert at the bottom to release nutrients slowly.