Do ferts degrade when exposed to light?

[fishbro]

Hey, so this may be a dumb question, but I have heard people say before that fertilisers should always be kept in opaque bottles as it prevents the light from affecting them. Is there any truth in this?

I am auto dosing and just drilled a hole into a water bottle to use as a container, so it's got me thinking whether that is having any ill effects on the ferts.

If it is, then I guess the ferts being held in the dosing tubing would also be affected surely? The tubes run up the side of the tank so get exposed to the bright light of the tank during the day.

Maybe it's a load of rubbish, but thought it might be an interesting topic to discuss

 

[dw1305]

Hi all,

I have heard people say before that fertilisers should always be kept in opaque bottles as it prevents the light from affecting them. Is there any truth in this?

There is, but only for chelated micro-elements where the DTPA, EDTA etc is degraded by light ("photodegradation").

You might have other chelated micro-elements (manganese (Mn) is sometimes chelated), but usually it is just iron (Fe) as a chelate.

Photodegradation is actually why the Fe++(+) ions become plant available in the tank, but in an all-in-one mix etc they will just combine with the PO4--- ions and form insoluble iron phosphate complexes etc.

cheers Darrel