Will raising the light have a big effect on PAR?

[Rube_Goldfish]

I am in the final stretch of setting up my 20 long Apistogramma honeymoon suite (I'll update the journal later). The hardscape sticks above the rim of the tank by about three inches (about 7.6 cm). When I planned the layout and bought the hardscape materials, I knew they'd be "too high" but thought it would look cool. What I didn't consider was that they'd get in the way of my light, a Hygger HG-999. I see that there are risers available on Etsy and Amazon, which I'll probably have to get.

My question, then, is about PAR with a raised light. I know that water roughly halves PAR for every six inches (about 15 cm) of depth, but that air has a much smaller effect. But the light's spread would also be greater. So is the difference in PAR between a light mounted, say 2 inches above the water and one mounted 5 inches above relevant, or am I worrying over something negligible? I'm not planning on a carpet or any particularly difficult.or high light plants, so I'm hoping I can get away with it.

Thanks in advance!

[Fish Folk]

On 10/27/2023 at 8:52 PM, Rube_Goldfish said:

I am in the final stretch of setting up my 20 long Apistogramma honeymoon suite (I'll update the journal later). The hardscape sticks above the rim of the tank by about three inches (about 7.6 cm). When I planned the layout and bought the hardscape materials, I knew they'd be "too high" but thought it would look cool. What I didn't consider was that they'd get in the way of my light, a Hygger HG-999. I see that there are risers available on Etsy and Amazon, which I'll probably have to get.

My question, then, is about PAR with a raised light. I know that water roughly halves PAR for every six inches (about 15 cm) of depth, but that air has a much smaller effect. But the light's spread would also be greater. So is the difference in PAR between a light mounted, say 2 inches above the water and one mounted 5 inches above relevant, or am I worrying over something negligible? I'm not planning on a carpet or any particularly difficult.or high light plants, so I'm hoping I can get away with it.

Thanks in advance!

I think you do not need to worry, especially given the plans. Apistos generally do fine with little greenery. Some species do like botanicals, leaf litter, and tannins. Best luck to you!

[Rube_Goldfish]

On 10/27/2023 at 10:58 PM, Fish Folk said:

I think you do not need to worry, especially given the plans. Apistos generally do fine with little greenery. Some species do like botanicals, leaf litter, and tannins. Best luck to you!

Thanks! Yeah, the plants are more for me than for them, I guess. But I'll plant them with confidence and see what happens!

[nabokovfan87]

On 10/27/2023 at 5:52 PM, Rube_Goldfish said:

My question, then, is about PAR with a raised light. I know that water roughly halves PAR for every six inches (about 15 cm) of depth, but that air has a much smaller effect. But the light's spread would also be greater. So is the difference in PAR between a light mounted, say 2 inches above the water and one mounted 5 inches above relevant, or am I worrying over something negligible? I'm not planning on a carpet or any particularly difficult.or high light plants, so I'm hoping I can get away with it.

It's definitely not a big deal.  I added a suspension kit to my light and it's helped me a lot with getting full coverage on the tank.  Essentially, the light raised up is at a "better angle" than it would be normally.  Some people with deep tanks will end up using one light to push the back of the tank and a second light to cover the front of the tank.  I think lifting it helps a bit so you can turn the one light up, push more PAR, but then you just have shallower angles (better refraction) so the light can actually penetrate deeper into the tank.

Hopefully that makes sense.