Unexpected PAR readings on my redsea 300xl with Kessil a360x's

[anthonymckay]

Ended up finally buying a PAR meter (Apogee MQ-510) and was pretty shocked at how low the par was coming off my dual Kessil a360x's. I've had my lights mounted 8" above the water set to 75% intensity, with the blue/white slider all the way to blue (0). This is on a Red Sea 300XL tank, sand to water level is ~21". At the highest points of my rocks (~7-8" below the water surface) where my sps frags are mounted I was barely hitting 140-160 par. Down at the bottom where my zoa's and such are I was registering ~60-80par. I played around with various configurations of settings and found that I had to crank up to full 100% intensity to hit 190+ par at the top of my rocks. If I turned the white lighting up to 50% it would hit about 210-230. This is not at all what I was expecting to see and left me scratching my head a bit. I really dont like 50% white lighting, but I'm thinking I may need to slowly ramp up my intensity over the week or two to 100% and run 50% white lighting for at least half of my peak hours. Curious if any one else has testing out kessils with a proper par meter and if these numbers match what you've observed?

 

[T-J]

Here's a BRS video on the lights that might help:

 

[A_Blind_Reefer]

There have been a few posts threads on this. Several have concluded that Kessils can not be accurately measured for par output using that tool as the spectrum they produce is not correctly picked up by that sensor. You could search for that across the forum, there are even some YouTube videos on it. It’s been known for years. Wether you buy into that or not is a personal preference I guess. I can state from personal experience that they can and do grow sps perfectly fine.

edit. There’s a couple videos on par vs pur that go into this a little more

 

[anthonymckay]

Just out of curiosity I hooked up my old A350 from my old biocube and set it up between the two A360x's on the reefer 300. Turning everything up to 100% blue gave me 300+ par near the top where my sps frags are. I think 3 kessils just aren't enough coverage for a 36" tank. I had a rep from Kessil reach out to me on fb and suggest also using some 55deg focus lenses as well on this tank to narrow/intensify the light spread. I will keep an eye out for a second hand a360x on my local reef group as they pop up from time to time and probably add that to my tank.

 

[A_Blind_Reefer]

Just out of curiosity I hooked up my old A350 from my old biocube and set it up between the two A360x's on the reefer 300. Turning everything up to 100% blue gave me 300+ par near the top where my sps frags are. I think 3 kessils just aren't enough coverage for a 36" tank. I had a rep from Kessil reach out to me on fb and suggest also using some 55deg focus lenses as well on this tank to narrow/intensify the light spread. I will keep an eye out for a second hand a360x on my local reef group as they pop up from time to time and probably add that to my tank.

That’s odd. I’ve seen many 24” cubes running a single a350x with stunning results. There’s always a t5 hybrid. Which is my personal favorite.

 

[rtparty]

In the end, they are only 90w lights and you're not even sniffing using that full 90w per light.

No matter what any manufacturer claims, it takes more than 180w to light a 3 foot tank properly.

I've read the whole "Kessils don't measure correctly" but any decent LED out there has a spectrum close enough to the Kessil and they seem to read correctly. The Kessil doesn't have that much light in the lower 400nm's to totally throw off readings.

 

[A_Blind_Reefer]

You’ll most likely want more opinions than @rtparty and mine. RT is a metal halide fan, and I’m a kessil t5 fan (well truly a metal halide fan as well, I just switched to the dark side). Regardless of our personal preferences, both are great ways to grow corals. Albeit, kessils really benefit from supplemental lighting. I never had the 360, but I did have a single ap700/power compact hybrid on a 48” mixed reef for about five years and then two ap700s with t5s on a 160 in a mixed reef with great results. I decided to go sps dominate so I went for the a500x/t5 hybrid recently and am very pleased. The ap700 is basically two 360s in a panel. My 160 is 24” deep and the ap700s did not have enough power deep in the tank for a mostly sps tank. My personal preference for best lighting with no considerations would be halide with t5s or led bars.

 

[rtparty]

I ran an A360X between two tanks for over 6 months. The 24*24 spread is a pipe dream. I found one Kessil for every 12" of tank was the sweet spot. So 3 A360X for a 3 foot tank. Tank width will also play a role here

 

[Jedi1199]

My new tank is a 6 foot 135.. 24" height. I plan to run 4 Kessil A360xTBs and 2 Wills 165s. I may add the 3rd Wills I have on hand if I find I need it (or for symmetry) .. I may run the 3rd just to make it all look even.

 

[A_Blind_Reefer]

I ran an A360X between two tanks for over 6 months. The 24*24 spread is a pipe dream. I found one Kessil for every 12" of tank was the sweet spot. So 3 A360X for a 3 foot tank. Tank width will also play a role here

Ah, I misread. I thought he said three Kessils would not be enough for a 36”. Yeah, supplemental is pretty much a necessity with Kessils in my opinion. The 500 barely makes the 24” spread for full sps. I thought he was only putting sticks up high.

 

[A_Blind_Reefer]

My new tank is a 6 foot 135.. 24" height. I plan to run 4 Kessil A360xTBs and 2 Wills 165s. I may add the 3rd Wills I have on hand if I find I need it (or for symmetry) .. I may run the 3rd just to make it all look even.

If you’re going full sps at 24” deep I would look at the a500x. Three 500s vs four 360s is about the same price wise. The 360s struggle to hit the bottom. Mixed reef, no problemo

 

[rtparty]

Ah, I misread. I thought he said three Kessils would not be enough for a 36”. Yeah, supplemental is pretty much a necessity with Kessils in my opinion. The 500 barely makes the 24” spread for full sps. I thought he was only putting sticks up high.

Kessils are extremely point source and require supplemental lighting like you said. T5s or LED bars of some kind are an absolute must IME

 

[damsels are not mean]

There have been a few posts threads on this. Several have concluded that Kessils can not be accurately measured for par output using that tool as the spectrum they produce is not correctly picked up by that sensor. You could search for that across the forum, there are even some YouTube videos on it. It’s been known for years. Wether you buy into that or not is a personal preference I guess. I can state from personal experience that they can and do grow sps perfectly fine.

edit. There’s a couple videos on par vs pur that go into this a little more

That doesn't really make sense to me unless I'm missing something. The spectrum in those kessil fixtures is not unique at all and pretty similar to most reef led fixtures. There's not even any UV in them

 

[Jedi1199]

If you’re going full sps at 24” deep I would look at the a500x. Three 500s vs four 360s is about the same price wise. The 360s struggle to hit the bottom. Mixed reef, no problemo

Agreed.

Problem is I am repurposing the 2 A360's I already have, and have already purchased the 2 new ones for the new build.

My tank is a mixed reef, mostly LFS with a few SPS, and heavy on fish. The SPS I have now, is doing well with what I have. The additional volume and more than double the footprint plus the extra 4" height would mean a decidedly significant upgrade to run a full SPS system.

 

[HB AL]

I have a solution for you.

 

[Jedi1199]

I have a solution for you.

A bit above my paygrade though... I think with the 4 Kessils and the 3 Wills I have, I should be fine for what my tank is.

 

[A_Blind_Reefer]

That doesn't really make sense to me unless I'm missing something. The spectrum in those kessil fixtures is not unique at all and pretty similar to most reef led fixtures. There's not even any UV in them

I don’t remember the whole scenario, something about the apogee sensor vs a full spectrometer. Also, the x series lights do have uv.

 

[anthonymckay]

Ah, I misread. I thought he said three Kessils would not be enough for a 36”. Yeah, supplemental is pretty much a necessity with Kessils in my opinion. The 500 barely makes the 24” spread for full sps. I thought he was only putting sticks up high.

oops, you're right, I did say that! But it was a typo, meant to say TWO kessils aren't enough for 36" based on the data I'm collecting.

 

[Spare time]

You were running them at 75% intensity. I am not sure why its a surprise that the par is not higher. Just turn them up. You can run 100% intensity and not increase the white. Just keep the same color settings. The 100% intensity values sound right to me. If you'd like to boost this, consider adding the reef brite xho's (or if hanging the light, the quantas or orpheks)

 

[A_Blind_Reefer]

oops, you're right, I did say that! But it was a typo, meant to say TWO kessils aren't enough for 36" based on the data I'm collecting.

Ah, @rtparty also has telepathic powers that I don’t posses! Haha I agree that two units, especially without supplemental lighting would be lacking in the full blown sps department.