Halides

[Matthias7]

i am thinking that I would like to change my lighting setup. I currently run with 3 kessils 360we's and 4 48in t5's over a 250 gallon deep dimension tank. I may switch out the t5's and run the kessils to supplement halides. My question is how many watts per lamp would I need 250 or 400? I plan on using the new reef brite controllable ballasts.

 

[hybridazn]

It really depends on what you want to spend on electricity haha, either one will do the job quite well. I prefer 250w halides for the fact that you don't need them to be really high up off the surface of the water and you get less light spill out of the tank if you don't have a canopy.

 

[Matthias7]

I would prefer 250's but I have not used halides before and I don't want to be underpowered

 

[hybridazn]

I would prefer 250's but I have not used halides before and I don't want to be underpowered

You'll be fine with the 250s on your tank.

 

[mcarroll]

You don't specify mounting height and this matters a lot. How high are your wide-lease Kessils?

I don't know how much is known about specific bulb performance on dimming ballasts, but assuming performance is 1:1 for what is expected and that dimming conserves bulbs life (all sounds too good to be true in real life), I guess you should go for the dual-400w setup and dim them according to a lux meter.

Can't help myself here, so apologies in advance... ;)

You don't think that 4 simple Kessils would outperform what you have currently? Seems like it should.

One Kessil is 90 watts • 3 is only 270 watts for (4 • 3.1 = ) 12.4 square feet of tank surface...assuming you aren't spilling much light (wasting watts) over the sides. 270 ÷ 12.4 = about 22 watts per square foot. Some lux readings would be instructive, but even just on watts I can tell you that's not a lot of light.

My low light LED tank only gets 13 watts per square foot but uses much stronger 30º lenses....the high light tank gets around 35 watts per square foot via 90º lenses.

A fourth Kessil brings you into the right target range at 29 watts per square foot. That should be great for most tanks...and at $1600 isn't too bad in cost for a tank your size. A fifth Kessil would give you a greater range and still only bring the system to $2K. ($8/gallon? :D)

You might get more bang for your buck out of the Narrow config going this route...

What about two Kessil AP700's? Only $1800 and could be more ideal.

Just some thoughts!

 

[Matthias7]

I love my kessils and can't see running my tank without them but for my tank I get much better growth with a supplement to them. I really like the option of not being tied to one specific type of lighting. The kessils and t5's work well together but my makeshift t5 setup is starting to fail and needs replaced. I though about the new kessils but I would still supplement them.

 

[mcarroll]

You are currently under-covered with respect to the Kessils, so the difference with supplements makes sense. I don't think it's the presence of the supplements per se. Just my opinion on what little I know about the situation, but the data seems to stack up.

Since the failing T5 system puts you in this position, I would add at least one additional Kessil - if budget allows, consider two more.

BTW, do you know what the total wattage of your current lighting system is LED+T5, et al?

For whatever replacement lights you get, use a lux meter to match your intensity you have now - which you should be sampling with a meter asap since the T5's are failing, you don't want to be stuck guessing what your light levels were after it fails - and then if you still don't like the all-LED/all-Kessil solution in however long before you decide, you can always unload from one to all of them and do something different. From what I can tell, used lighting seems to move pretty well.

As I said, I really think the lack of power on the Kessil front is getting you...so it's worth a shot IMO. Much more streamlined, for what that's worth. :)

I understand there's more than one way to skin a cat too though! :p

P.S. Start with a downloadable lux meter since you can do that and get readings right now. Readings from a decent one are good enough. It's worthwhile and better (except for the wait for shipping) to get a $15 handheld though...search for a "lx-1010B".