Need help with new LED light fixture

[dogmajones]

I was on my 20 gallon long running a 4 bulb t5 light. I have since upgraded to a 40 gallon breeder, and with it an ocean revive arctic t247 LED light. the major issue I am having with this light is knowing what is too much, and or too little light. I am surprised my corals haven't died yet I have been changing the intensity's almost daily. I have a branching hammer coral that was having issues even before the upgrade, it has about 5 heads that are splitting and has stopped openly fully, I am hoping it's due to the splitting of the heads. the only coral I have that I can judge if my light is too high or low is my elegance coral, as it is the biggest coral currently in my tank, and it opens fully every day, so with an elegance coral do I judge bu the length of the tentacles the amount of light it is receiving? example at some settings it's tentacles seem much longer then others. I am currently running the light about 18 inches above the water, and have blue channel at 45, and my whites at 10. I am having a hard time telling is is too little or too much light. I really should get a par meter to test things, but they are so darn expensive, so does anyone have any advice on how to tell if I have my lights too high, too low etc, the corals I have currently are.
4 acans on sandbed middle of tank
1 Aussie elegance on sandbed left side
1 torch coral about 6 inches off sandbed on a rock
2 branching hammer coral right side about 8 inches off sandbed
1 favia coral right side about 4 inches off sandbed
1 Purple star polyps on its own rock about 4 inches off sand bed
so with this list of corals, what should I be looking for when adjusting the light intensity. I am still very new to LED lighting, and am a bit ocidsh when it comes to my tank, thus the constant changing of intensity's, could really use some sound advice for both my own sanity, and the life of my corals.

 

[Vinny Kreyling]

Looks like you have mostly LPS.
They do not require LOTS of light so start out on the low side like now.
Leave it alone for @ least a week before changing it, & then gradually, no drastic changes.
There is information here if you do a search.

 

[dogmajones]

is there a negative to running the white channel very low. I have heard many go about 1/3 on the white channel as they do the blue channel.

 

[Vinny Kreyling]

The blue spectrum is supposed to be more beneficial in coral growth.
It also has the benefit of showing coral in a different light that some like.

 

[OceanRevive]

Hey dogmajones, there is a par reading of T247 on our website which can give you a general idea of how much par you could get at different height (http://www.oceanrevivellc.com/goods.php?id=21). But the intensity is at 100% for both blue and white. Given your tank is not too big, a low setting should give you a good par reading about 100 from the bottom of your tank. Normally we recommend to start with 40% blue and 20% white and observe how everything reacts. If they look fine and bloom more, then you can increase the intensity 10% per week or two. But if you only want 100-110 par on your sandbed, 40% blue and 20% white should be able to do the work. However, it is hard to guess the exact number without a par meter reading. Hope this helps.

 

[Ron Reefman]

dogmajones, I have an OR S026 (older version of the T247 but same leds) 18" over my frag tank (only 10" deep). I run 90% blue and 20% white and my corals do just fine. BTW, I do have a PAR meter if you need more help.

 

[Tanker1961]

Hey guys, newbie here trying to figure out my blues and white lights. I do have the T247 but am having troubles. Just a day after getting my light I've had 6 strokes so I'm struggling on programing.
Mainly I'm having troubles trying to changing the intensity after its been programmed. Is there a way to reset back to factory settings? Thanks all