Quick Lighting Question

[Devilish]

I have a 40 gal high tank that is 24" deep. I am currently running a 400w 20000K MH. I am going to change over to a 10000K MH and 2 actinic VHO's. I was wondering if I should go with 2 55W or 2 96W actinic VHOs. Also, does this seem like over kill on the lighting? Also, the lights are mounted 13" above tank level. Thanks in advance.

[Amphiprion]

Well, that much certainly isn't necessary to get good results, but there's no reason to get a different setup with what you have as it is. Just carefully acclimate everything when you switch to 10Ks, since the increase in PPFD will likely be quite large.

[Ace25]

Wow, there is a thing as "too much" lighting. I am finding that out myself, with 400w of 10k MH on a 75G reef. There are many corals I can not keep due to too much light. My tank is 24" deep as well. My light is mounted 15" above tank, with 4 T5HOs for actinics.

I would seriously reconsider going to a 10k 400w on a 40G tank. That is going to be around DOUBLE the light output (PPFD) of the 20k you have on it now. I think the 20k is fine, but even that is pushing the limits of too much light on that size tank.

[Amphiprion]

Yeah, I figured it would be a very large increase. You'll have to acclimate very carefully--it can be done, but it certainly won't be easy.

[Devilish]

Thanks for the input, I actually just got done cycling the tank so there is no inhabitants in it now. I've been playing with a few things and trying to iron out all the wrinkles before I start stocking. Was just worried about the 20k hindering the growth of any corals I may add. Figured the 10k would allow for the proper lighting for growth and the actinics would provide the bluer tone for better viewing, personal opinion.