Interesting, is there any benefit you’ve seen to keeping your Gonis under higher light intensity?i‘ve got a mixed reef with mostly lps and I keep the par near the bottom in the middle around 200. You can ramp the PAR a bit. Here’s the PAR readings. I’ve got torches and Gonis in much higher par than that
Well they certainly don’t seem to mind it for the most part. It partially seems to depend which vendor I’ve gotten them from. These is are the ones at 279 par
Careful when you add the reflector lens to the a360x, it concentrates PAR pretty drastically, so make sure to start low and acclimate up. Clam will thank you for it! And derasas get so big it will fill in that "spotlight" space, no problem.
I’m pretty sure I have that same pink Goni, one of my favorites. I think it was used to higher par it was kept in an SPS tank. May try to move it up a bit and see how it does.Well they certainly don’t seem to mind it for the most part. It partially seems to depend which vendor I’ve gotten them from. These is are the ones at 279 par
No. Because Goniopora are commercially aquacultured for the medical field, there is a lot of research about them. They only need ~90 PAR in the violet/blue spectrum for 6 hours a day. Anything else doesn't affect growth. That being said, mine are under 200+ just due to the nature of my aquarium. It doesn't harm them, it just doesn't lead to an increase in growth.
Clams don't need acclimation. They're farmed under direct sunlight at 1000-2000+ PAR, hobbyists are unlikely to hit that. They also self acclimate if need be by reducing mantle extension and/or producing more light blocking pigments.
and we all know that 3 XR15s are plenty of light for a shallow 4' frag tank 
Thanks for explaining it this way. I will be doing more research on clams, as I’ve found out I don’t know much.We need to change the way we think about lighting clams in terms of numbers, just like water parameters have a wide (acceptable) range to create good chemistry, clams have a wide range of intensity in which they can grow. Whenever I see a number thrown out in regards to lighting clams, I kind of cringe, because it sends the message that it's the goal and the clam will grow just fine. This isn't the case at all. We need to stop thinking of bare minimums when lighting clams, we need to think about health. Clams receive well over 100% of their nutrition from their mantle (simplified version), which is driven by light. So why would you barely give it what it needs? That's like putting 2 gallons of gas in your car, expecting to make a 200 mile trip. The par numbers that most people read are minimums and not the end goal. Ultimately, the clam will tell you if you have enough light or not. If you don't see new shell growth in a matter of days, you simply do not have enough light. All clams (especially smaller ones) will have active growth margins that you can visible see and measure over the course of a few days.
To give an example, I brought home a derasa that was around 3" from a LFS (traded some duncan frags for it, win, win), the clam looked healthy, but there wasn't any growth on the shell. I told the employees that they needed to give their clams more light (as most of the clams barely had any new growth). They kind of shrugged it off, as they said the lights looked really bright to them
After putting the clam in my 10g nano, it only took a couple days and it grew 2mm. So the numbers you see should be starting points, not the end goal. Feed your clams plenty of light, lots of light and they will grow and be happy, healthy clams.
I don’t think you need that much power. I would start at 250+ and see how the clam does. If you don’t see new growth in a couple days, increase by 50-100 micro moles. Also, but James Fatherree’s book on clams from Amazon.
My clam has been happy and open under those lights so I’m not changing anything for the time being. I did add the 35 degree reflector though, man does it do it’s job.
As long as you see new growth on the shell, you’re good to go. A clam that small, you should see a good growth margin.
