Purchasing Lighting

[Snappy]

I have a 40gal reef tank with 20gal sump and I am considering upgrading my lighting. Currently I have a 36" 95watt actinic PC and a 24" 65watt 50/50 PC. I want to get something that is going to make my corals their bright neon colors. I am not quite sure if I want to get metal halide, or VHO. Is there a big difference as to whether one is better than the other as far as photosynthesis is concerned, also which one will make my corals bright and neon. Finally, what would be the cheapest way to get a 36" setup?

[Geoff]

what kind of corals do you have? you have such a high percentage of actinic i am surprised that you are not flourescing more? it could be that you are two actinic and the corals are not getting enough PAR to be truely happy. have you tried a 10K on the 95w and an actinic on the 65w? you have 4w a gallon, which is decent, not spectacular, but not bad either. depending on the corals you have it could be perfect.

G~

[Snappy]

I currently have candycane coral, green star polyp, various mushrooms and zoos, xenia, and 1 brown-branching coral. I plan on increasing my tanks population. It seems like the GSP and candycane appear to fluoresce more when just the actinic is on.

[tdwyatt]

Originally Posted by Snappy

...It seems like the GSP and candycane appear to fluoresce more when just the actinic is on.

yup!

Increasing the percentage of the actinics ( the 03 type of bulbs) in the VHO setup will increase the reflectance fluorescence of these corals. Some specimens will fluoresce more than others (as you've already found out), and some specimens will fluoresce more when they are in their best state of health, so it is just as important to include a good amount of PAR each day (with a good daylight bulb) as it is to provide the wavelength of light that stimulates fluorescence as Geoff has already alluded to.

The most effective way to do this with the octocorals you listed is with a mix of VHO bulbs, as even with stony corals, many aquarists will add the 03 actinic VHO's to encourage fluorescence and "blueness" in the display while using MH in the 10-14kK color range for PAR.

HTH

[Snappy]

What is PAR? Also, would you know where to get the cheapest VHO setup (online or auctions etc...) and how much it would be for a double bulb 36"?

[Snappy]

My tank is an acrylic with the 4" or so lip around the entire top and two 8"x11" openings. I currently have two large pieces of glass covering these two openings which prevents evaporation and creep. It may also be preventing fluorescence amongst my corals. Any advice?

[Geoff]

i would remove the glass covers for starters. any amount of salt on the glass greatly diminishes the effectiveness of the lights.

G~

[tdwyatt]

ditto on removing the glass covers, make the system open to the atmosphere, not only does this dramatically improve light transmission, but it will also improve temperature control (improved evaporation rte keeps temps down) and resolve chronoc low pH issues (due to poor CO2 exchange at the surface). Salt creep is usually only an issue if there is excessive splashing or bubble generation within the tank, and shul be easily resolved.


hth