Kessil a500x question

[SaltyGirlMom]

Bought this light and set it up this morning. Haven’t set up WiFi or the app yet to adjust the intensity/schedule, etc., but started wondering if this is really too much of a light (for my recently set up from combined tanks) 30g Watercube, or if this will work out fine, and wanted to reach out to those with more experience. My goal for this tank is to make it a mixed reef. The reason I chose this light over the A360X was because that only had a 24“ x 24“ range and the width of my tank is 31 1/2”. I thought this model would be best to cover the width, even though it is advertised as good for deep tanks and/or SPS heavy, which isn’t my current need.

It also looks like it sits too high to me, but the bottom of the light sits abt 13” above the tank, which is appropriate with the 55 degree reflector that came with it. My windowsill is right behind the tank, and stops the bottom of the mounting arm from coming down further, and I don’t really want to move the tank forward in order to accommodate it to come down past the sill because then the tank will look cumbersome on my counter (when moved forward). Would also be a task to half empty in order to move forward. Does it look too high (or large or off in some way for the size of tank to anyone else?)

I don’t have a lot of experience with buying lighting and never a Kessil so TIA. (Ignore cords which will be hidden under sill in future!)

 

[SpacedGhost77]

You’re in a good spot. The A500X is not excessive for your setup. It’s actually a strong match for what you’re trying to accomplish.

With these lights, spread is determined primarily by the reflector choice and mounting height. The fixture itself has more than enough output, so it’s really about how you distribute that light across the tank. At approximately 13” with the 55° reflector, your mounting height is appropriate and should provide solid coverage for a tank in the 3’ x 2’ footprint range.

For reference, I’m running a similar footprint (Red Sea G2, roughly 3’ x 2’), and the light has no issue covering that area when mounted appropriately.

This is not even my final configuration, but I’ve been using the light to support a mini cycle. In my case, I’m running it over 2 feet above the tank with a 35° reflector, and it still covers the footprint effectively. That setup actually surprised me in terms of usable spread.

It’s also worth noting that running LED fixtures at maximum output continuously is not ideal. Maintaining some headroom improves efficiency and can help preserve long-term performance, particularly in the lower wavelength spectrum.

In my experience, even when running a tighter optic, increasing mounting height allows the light to cover a 2–3 foot footprint effectively. Once you configure your schedule and intensity, the system will feel much more balanced.

Overall, I think this is a well-chosen setup. You have both the coverage and the PAR capability. At this point, it’s simply a matter of dialing it in to match your livestock and goals.

Out of curiosity, what other lighting options were you considering? I’ve worked with several different systems (Radion, Orphek, Reefi, Red Sea, halides, etc.), and I’d be happy to offer a comparison if helpful.

 

[SaltyGirlMom]

Thanks for the info! I didn’t look around beyond Kessils much because I understand they are pretty solid and sought after. I do agree that the 500 would be perfectly fine for what I’m trying to accomplish, but I couldn’t get past that it didn’t look proportionately sized over my tank (looked clunky). I spoke with someone at my LFS and he advised doing two 360s instead and said he found that one light for every 24” visually looks best. This made total sense and then I spoke with the company I purchased it from abt an exchange and that guy said he had a set up like mine and that he used the ap9x and was sure that it would look best. I do believe both lights would work so now I’m trying to figure out what will actually look best over my tank, which may just boil down to personal preference. The rep said he always advises the ap9x over two 360s because he found that lighting set up to look better inside the tank also, that it’s a slight upgrade in some way from the two 360s. Thoughts?

 

[SpacedGhost77]

Thanks for the info! I didn’t look around beyond Kessils much because I understand they are pretty solid and sought after. I do agree that the 500 would be perfectly fine for what I’m trying to accomplish, but I couldn’t get past that it didn’t look proportionately sized over my tank (looked clunky). I spoke with someone at my LFS and he advised doing two 360s instead and said he found that one light for every 24” visually looks best. This made total sense and then I spoke with the company I purchased it from abt an exchange and that guy said he had a set up like mine and that he used the ap9x and was sure that it would look best. I do believe both lights would work so now I’m trying to figure out what will actually look best over my tank, which may just boil down to personal preference. The rep said he always advises the ap9x over two 360s because he found that lighting set up to look better inside the tank also, that it’s a slight upgrade in some way from the two 360s. Thoughts?

You’re on the right track, and honestly this is more about preference than capability at this point.

I agree with you that multiple point sources tend to look better over a tank like yours. The A500X will absolutely grow anything, but visually it can feel a bit bulky and “spotlight-ish,” especially on a smaller footprint. That’s just the nature of a single high-output point source.

That said, I don’t think the AP9X solves the issue you’re describing. It’s still a large fixture, and if your concern is the overall visual weight over the tank, it’s actually going to feel bigger, not smaller. Where it does win is spread and uniformity across a longer footprint, but it doesn’t really get rid of that “one big fixture” look.

Two A360s makes a lot of sense from a visual balance standpoint. You get better distribution, less shadowing, and it just scales more proportionally with the tank. If you go that route, I’d lean toward the A360XE so you have more flexibility with mounting height and spread.

One thing that helps a lot, regardless of which direction you go, is mounting higher than you think. I almost always run my Kessils higher than typical recommendations. It softens the hotspot, improves blend, and gets rid of that heavy look hanging over the tank. You trade a bit of intensity, but these lights have more than enough output to compensate.

So if I had to rank it based on what you’re trying to solve:
• Best visual balance: two A360s (preferably XE)
• Best single fixture performance: AP9X
• Maximum punch but more “industrial” look: A500X

At this point, you’re not choosing between right and wrong, just the look you want over the tank. It’s hard to judge from photos and videos alone. Seeing it in person is what really decides it. At least now you know the A500X isn’t the look you’re after, which narrows things down.

Let me know what you end up going with.