Repurposing old Kessil A150W spotlights for LPS and Clams on sandbed 24" depth

[nickijon]

I need some lighting pointers after being out of the loop for 5 years or so.

• We've moved from a 40B (16" height)
• Now setup a 120g Eurobraced Peninsula

Current lighting consists of the following.

• 4 Kessil A150's, 10k Sky Blue color temp
• 10am to about 11:30am natural sunlight through high bay window hitting about 1/3 of the tank

From older RC threads, a single A150W hits about 70 par for a biocube 29's sandbed, about 20" height.

Is our light setup enough for our 2 Derasa clams? I've noticed a bit of retracted mantle over the last week or so, and am worried they are getting starved of light. Moved them over to the patch of sandbed that receives natural sunlight. They look a bit happier after 24 hrs in their new location.

Of the 6 Kessil A150W's that came out of storage, 4 of them are salvageable. Prioritizing effective solutions vs. aesthetic and expensive solutions.

Any tips, recommendations, analysis you all could share? Much appreciated in advance..

 

[dwest]

It depends on a lot of things like tank depth, mounting height, and tank dimensions.

A PAR meter will help you decide. I think you need at least 100 PAR on the sand for derasa. 200 is better.

I had kessil a150‘s then upgraded to the 360we ‘s then put the 360’s in an aquatic life T5 system. During almost all of this time, I had derasas on the sand bed (over 10 years). So, my opinion is that you might have barely enough light. But I would feel more confident with them with some T5’s or other additional light.

 

[dwest]

Edit, I just saw the tank is 24” deep. I don’t think that a150’s alone will work for the clams.

 

[nickijon]

Thank you! We'll be installing the Aquaticlife Coral Cover LED's with two Aquaticlife Core XP Marine fixtures inside them. It'll be a LOT more light, I think!