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Overdriving the bulbs produces a lot more par & as mentioned they only last about 6 months versus 12.
I get about 200 more par when measured with a par meter just under a single bulb vs an ATI ballast.
The blue+ bulbs will run a little less blue but it's almost un-noticable visually and my tank will look a tad brighter. I don't know if the secptrum is much different.
The overdriven bulbs/ballasts are making a slight resurgence because VHO is going away and people with deep tanks that were using VHO supplementing can transition to T5. If you haven't noticed Coralvue has re-introduced the 660 ballast and also the DIY kits are available.
The range I target is between 250-450. Up to 550 is ok but only certain Acros will tolerate that. I like the deep vivid colors, versus pastel.
300-350 is the sweet spot range......Most will have good color
Millis color best at the higher levels
Smooth skin acros can do very well in the250 range.
I run the lights 8 hours a day, all on/all off.
Here's the par numbers I was getting in my 75g----
The lights are 6 1/2" from the surface and total water depth is 18 1/2". The first number is the level from the floor of the tank. The number in ( ) is the distance from the bulbs.
1" off the bottom-- 200 (24)
3"- 260 (22)
6"- 280 (19)
10"- 300 (15) This is mid level area of the tank.
11"- 325 (14)
12"- 360 (13)
13"- 400 (12)
14"- 430 (11)
15"- 470 (10)
17"- 500 (8)
80g rimless current tank – light 8.25” from water surface
5” off bottom- 300
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You're 8 bulb fixture will be plenty.
Big E -- That's very helpful and I appreciate you taking the time. It reconfirms my thinking that the 300-350 range is my sweet spot. I've built some new multi level frag racks to accommodate for this lower target.
My Subpower 8bulb arrives tomorrow and I'll start getting the new tank plumbed into the sump. Going to use this as a guide. Think we have the same tanks.
Thanks again!!
Hey BigE Just went through your RC build very nice and great information. I plan on adding your 4bulb combo to my system with some leds. I also have been looking for some useful par values with no luck (all I find is 500-800par) which I know is a bit much (I'm running a low nutrient system) Thanks again
Hey Cola.
I just switched out some bulbs and changed from purple+ to the actinic...here is my current combo...72" 12 bulb light, 6 on each side
Actinic
Blue+
Blue+
Coral+
Blue+
Blue+
Growth hasn't slowed down at all.
I might change out another set of Blue+ for Actinics. I change out 4 bulbs every four months, for budget and light acclimation reasons.
that has to be one of the nicest 75 gallon sps tanks I've ever seen what bulb combo are you using? also what method are you using to keep cal alk and mag up with all those beautiful acros eating it up and any other additives you use8 bulb dimmable ramping down for the night
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I just switched all my bulbs to only Blue+ and Actinics T5's in a 50/50 ratio. Anyone else try this before? What do you guys think will happen?
I know Cornbred does the same thing with only running blues and actinic LEDs.

