Terrestial plant fertilizer for planted aquarium use?

[kajaksurfa]

Hello,

My plantshop (terrestial plants) has a liquid fertlizer (Substral Iron+)
250 ml / 35 SEK= 3,5 £
containing per 100ml:

N: 7.1g
P: 1.5 g
K: 5.9 g
Mg: 0,2 g
Fe: 35 mg
Mn: 10mg
B: 10mg
Cu: 5mgr
Zn: 2mg
Mo: 1mg

Could this be diluted with destilled water and be used as fertilizer for aquarium plants?
Is there a risk that the included elements is toxic depending how they are bound to each other chemically?
(more even so to the fish I presume)
What are the pro's and Con's with using terrestial plant fertilizers in aquaria? Anyone tested?
What are your experiences?

Best Regards Leif

 

[ceg4048]

Hi,
Yes, you are absolutely correct. The toxicity will depend on how the elements are bound. You have to be careful with terrestrial products because the source of the N is often an ammonia salt. Try to find out exactly what the actual salts in the product are, not just what their equivalent elemental percentages. you need to know that before any analysis can be performed on dilution.

Cheers,

 

[dw1305]

Hi all,
Most horticultural liquid fertilisers will use Ammonium nitrate (NH4NO3) as the nitrogen source. This is because you get "more bang for your buck", as it contains 33.5% N., and is very soluble. The other advantage is that it it isn't a very "salty" salt and has a proportionally lower effect on the conductivity of hydroponic solutions than potassium nitrate would (hydroponic nutrient solutions are a lot more concentrated than tank water and typically have conductivity levels of 2- 7 milli-siemens ).
cheers Darrel