Surface agitation and light

[idris]

I sure I'm way off the mark here but ...
Half of my tank has significantly more surface agitation than the other half. When sat in front of the tank, I've noticed that there is a lot more internal reflection on the half with less agitation.
I realise polarisation at the water surface and viewing angle are likely to be significant factors, but in terms of light reaching plants, is surface agitation even vaguely relevant?

 

[Nick potts]

but in terms of light reaching plants, is surface agitation even vaguely relevant?

Likely not, I am sure surface ripples cause light to bend/deflect in different directions, but I would guess that any effect has on plants is minuscule.

 

[jaypeecee]

...but in terms of light reaching plants, is surface agitation even vaguely relevant?

Hi @idris

Interesting question. The physics here is complex, to say the least. Refraction and total internal reflection on a moving surface! I suspect the only definitive way of answering your question would be to take a measurement underwater using a suitable PAR Sensor. So, in reply to your question, my reply is - I don't know. But, if I ever get round to buying the PAR sensor that I keep promising myself, it's something I could check out.

JPC

 

[Nick potts]

BRStv Investigates: Should PAR Testing Be Done In Air Or Water - What's Best?

Today on BRStv, we have a brand new episode for our series, BRStv Investigates. In this series we explore popular reefing theories, products, methods, and what the manuals are missing, with a focus on putting them to the test! This week we are taking a dive into PAR testing lights and if that...

www.bulkreefsupply.com

The above video has some tests done in water, and at the end in water with surface agitation/ripples in particular, with minimal difference.

 

[MichaelJ]

Circulation / agitation definitely influences light scattering, but I would consider the effect practically negligible in a planted aquarium, in terms of the amount of light your plants will receive - I highly doubt that a PAR meter would even be able to pick up the difference within its tolerance range. Now, if your circulation/agitation is so high (extreme) that it severely influences turbidity of your water column then it will of course influence the amount of light your plants will receive as well.

Cheers,
Michael