UV Light for Fish?

[russianaquarium]

Hello everyone, I set up another 10 gallon for my mystery snails, and put some plants in there, like hornwort and bacopa caroliniana, and some guppies. I had this very cheap light on it, basically 2 old lightbulbs on a lid very dim and yellow, very bad looking.... And I had this reptile light lying around in my attick, and its brighter than the light i had but not very bringht, is it safe for the fish? And what will it do to the plants? Snails? Thanks.

 

[jarrod0987]

I have been looking into this for the last few days because I found it an interesting questions. I did find what looked like an intro to a study regarding this.

The short version:
Plants can't use UV light to do photosynthesis. They need Red or Blue Light.
Exposing plants to UVB also caused reduction in there chlorophyll amounts. Not good.
Last, I have read that UV light can damage the DNA of the plant. Same reason we use it for treating parasites etc.

So I initially thought it would be just useless to plants but maybe beneficial for tank health. I did not realize at first it was the only type of bulb. I thought there was 1 normal one and 1 UVB one. I guess there is only one bulb type. I also now believe, after much reading, it is harmful to plants. Get 2 regular bulbs or Fresh water planted tank bulbs when you can afford it. Thanks for the interesting question.

 

[Ingy]

IVB light has very limited water penetration capacity. Just a few cm for a T12 bulb ( less than an inch) so it would not be harmful to plants. And if your tank has a glass or plastic cover, it will be blocked. You may see an advantage of more iridescence due to some additional UV light.
On my tank I run 2 Kessil 350 tuna blue lights. These are designed for corals and have UV light. Now mounted on my fresh water tank, the plants are growing exceptionally well. Even the Lilly pads show no sign of sun burning despite my lights peaking around 80%.

 

[russianaquarium]

Thank you all for your replies, I did add a led light so plants can get atleast something to grow on... will a 6 inch led strip of 8 (bulbs?) help plants grow? and how good is it for plants? (the led)