Sps color and radion

[Proteus]

I've been struggling with some color in my tank.
My red planet is yellow while others like my deswalli are great
Pink Floyd is green and not gaining any color

I have a 24x24x12 half cube. 90% of coral is 6" deep. The radion(gen1)is 10" above water. It starts at 3pm ramp for one hour to 10k at 70% going to 20k @ 80% by 10pm ramping down for 1 hour
I feed very little as I only have three chromis. The bioload is very light with skimmer only pulling after dosing coral snow. It's a prodibio tank


My params

Nitrate 0
Po4 undetectable
Ph who knows

Cal 450
Alk 7
Mg 1350/1400

I'm on the verge of buying a 250w metal halide but thought some gurus may have suggestions

Much appreciated.

[xenon]

When was the last time you tested for potassium?

From our experience, the more blue the light settings the better the color. If I could calculate the color temp of our settings it would be 24k.

You should consider adding more fish and feeding more.

[waynemah]

I recently switched to Hydras and the color was dull compared to my DIY (Royal Blue and Cool White). I found they lost luminescence and reds went away completely. I boosted the RB along with the Deep Blue and UV (now all blues are running at 80% with my whites at 100%, greens and reds peak at 30%). Colors have changed drastically within the last week.

The other factor is ALK for me, what are you testing with? The higher ALK the more pastel the colors get, with 9DKH being the breaking point for SPS health.

Do you have any pictures to show the colors?

[Proteus]

Haven't tested potassium. I do a water change every three days(5g) on 40g system

I test alk with elos

I was running at 20k but found I was getting more encrustation and less branching

I do also have a blue assessor but he only comes out in evening

Pick suck as I don't have good camera

[xenon]

You should make sure your salt is not deficient in potassium. We are currently using the new Fritz salt and it is highly deficient in potassium (290ppm) so we buffer it up to 400ppm and it makes a big difference in coloration.

I would start by adding more fish and feeding more. Either that or start broadcast feeding some oyster eggs and rotifers.

[MitchM]

Originally Posted by xenon

...
I would start by adding more fish and feeding more. Either that or start broadcast feeding some oyster eggs and rotifers.

I agree. Undetectable PO4 is not necessarily a good thing. Your corals could probably benefit from some nutrients.

[uniboob]

I have heard that corals don't like ramping of LED unless its a quick ramp up for lights on and a quick ramp down for lights off.

[MarkoD]

Your lights might be too bright. I'm running radions at 35% at 6 inches above water with a 20" deep tank. With sps 12 inches deep

[Proteus]

Originally Posted by MarkoD

Your lights might be too bright. I'm running radions at 35% at 6 inches above water with a 20" deep tank. With sps 12 inches deep

What color temp are you useibg Marko

[MarkoD]

20k