VHO lighting question

[wishmaster]

I have been thinking of the long term plans I want for my tank and I came to the conclusion that I want to go with some clams. I will have within the next week a VHO PFO Retro kit that holds four bulbs. Thats around 440watts of lighting. I have a 55 gallon tank with LR and a DSB. Is this enough light to successfully keep them? Also, what corals would NOT fair well under this lighting that way I'll know to stay away from them?

[Toooloud]

55 gallon tank, What is the Depth of that tank.. and how long is it?

VHO lighting is great .. But for clams im not sure, as for any tanks deeper than 20 inchs you would need Metal Halides. as VHO would not have Intesity that you would need..

In all honesty.. if you are planing on keeping that 55 gallon, your best Lighting would be concidering that Clams are among the most lighting needy creatures.. you would want 2x VHO Actinics. and 2x 250 watt 10k Metal Halides, the VHO would be best for the actinics, and the Metal Halides would give you the Penitration that you would need to get through out the tank.

Running that setup you would be able to keep anything your heart desires, Witch is allways the best.. becouse we allways end up seeing somthing that we would love to keep.. but then say CRAP i dont have eough light.. then end up looking to upgrade..

Personally, i have my 30 gallon tank going.. that im going to keeop some SPS and clams.. its 36 inch long, and with the DSB its only 12 inches deep.. and im running 2x 175 watt Halides and 2 VHO 36 inch actinics.

[agilis]

A standard 55 is only 20 inches deep. If you have a sand bed, the water column is even shallower. Four 48" VHO bulbs is a lot of light, especially concentrated in the relatively narrow width of a 55 gal. aquarium. There are very few corals which require more light produced by that concentration of VHO bulbs. Tridacnid clams have high light requirements, but should get all they need from your arrangement. If you have live rock, the clams can be positioned even closer to the light source. They may not grow as rapidly as they would under halide lighting, but they should do ok. Besides, some of those clams can get pretty big. I would be conservative about number and species.

Metal halides have a lot to recommend them, and I love the realistic ripple effect. They have a number of drawbacks as well, particularly the heat they produce. They can heat a smaller tank to the point that a cooler is needed to keep the temps within acceptable range, tend to evaporate a lot of water, and are more hazardous in general. VHOs are simple, produce very little heat, and simplfy the whole reefkeeping experience. I think you'll be fine with 440 watts of VHO over a 55.

[slipknottin]

Originally posted by agilis
They have a number of drawbacks as well, particularly the heat they produce. They can heat a smaller tank to the point that a cooler is needed to keep the temps within acceptable range, tend to evaporate a lot of water, and are more hazardous in general. VHOs are simple, produce very little heat, and simplfy the whole reefkeeping experience. I think you'll be fine with 440 watts of VHO over a 55.

fluorescent bulbs produce more heat/watt than Mh does.

[wishmaster]

Thanks for the advice, I think I'll go with the VHO lights. My wife kinda put me on a budget ever since the saltwater idea popped into my head. She will really freak when I tell her my 125 fresh is going saltwater too.

[agilis]

I would like to see more data in support of the VHO heat output exceeding MH of similar wattage. I use Icecap electronic ballasts, and the heat given off by the bulbs is only slightly warmer than a standard flourescent. The ballast is actually cool to the touch-while it's on. There is almost no appreciable transfer of heat to the water surface. Halides give off heat from the bulb toward the water surface. The fixture gerts hot, ,and a lighted bulb will cook your skin should you have the bad fortune to touch one. The ballast (which often hummmmms quite audibly) gets very hot. Used carlessly, or around kids, MH are dangerous. Fires are not unusual.

None of these problems exists with a good quality VHO system. Icecap and Ultraviolet resources sell top drawer stuff. Icecaps will also light regular t 12s, t8s, compact flourescents, and the new t5 bulbs, and light them better and brighter than any other ballast i know of. I get almost VHO performance from ordinary 36" 30 watt t8s, using Icecap elec. ballasts.

Whatever the heat/watt claims that are made, every MH I have seen is HOT, heats the water, and is an electrical and heat hazard if not handled very carefully. I have not seen any serious heat transfer using VHO, especially if you hook up a muffin fan. I have my 640 watts of vho over a 180 reef tank. I've been growing corals for 20 years. My lights shine through a glass canopy, to reduce evaporation during the two to three weeks trips i take every few months. My aquaria are practically self sustaining. This is not the case with metal halide setups.

Flourescent technology is just getting off the ground. Exciting new bulbs are on the horizon. Get a good heatless Icecap ballast and you'll be ready for anything that comes along. I have been using one, a 440 model, since 1992. it still works great.

[slipknottin]

heh. On the ballast front, you do know they make electronic MH ballasts that run very cool also, right? Nice push for Icecap thoughout your reply though... very smooth. I like the fulham ballasts more, and Ive used both...

Just look at the VHO bulb this way. A 4 ft bulb is running at 110 watts, a 5" MH bulb is running at 400...

Of course the MH bulb is going to have a higher temp. Thats how they operate. The VHO has way more wasted spectrum in the infrared area. They dont seem to be running as hot as a MH because the heat is distributed along the entire length of the bulb. The total heat output from them is higher than an MH, but the temp of them is lower.

I have never heard of anyone having a fire running MH. Properly setup they are extremely safe. You wouldnt want to touch the bulb, but then again you wouldnt want to touch a T5 fluorescent thats been running for awhile either. (I know, im running 4 54 watt T5s right now)

And about water evap... youd see just as much water evaporation if you took your glass panels out, so its really not much of a debate. You can run glass in bewteen a tank and MH bulbs too. Everyone who runs HQI bulbs does.

[agilis]

Just for the record, I have no connection with Icecap, which in any case makes some of those cooler electronic MH ballasts you mentioned. My comments were based entirely on my experience with my own aquaria, and observation/discussion with other aquarists. I admit my experience with MH is limited, and over a decade old. Perhaps great strides have been made since I used MH. Certainly, better MH color temps have been developed, particularly by the Germans and their imitators. Nevertheless, I notice that most MH applications seem to position the bulb rather far from the tank's surface, and MH users I know tell me they have higher evaporation rates with MH. Naturally, a covered aquarium will evaporate less water. In my limited experience, an uncovered MH tank evaporates more water than an uncovered VHO tank, and a covered MH setup will get hotter than a covered VHO, unless the MH is suspended well above the tank, an arrangement presenting it's own set of problems.

Most of the MH fires I've heard about were connected with ganja growers. I do think the high voltages and super hot temps of MH require more care to see that they are, as you say "properly set up". Maybe I'm too conservative, but I would feel worried about leaving MH unattended for a couple of weeks, just like protein skimmers, which I shut down if I'm going away for any length of time. My VHOs, which sit almost directly atop the cover glass, seem to need almost no attention, other than cleaning the bulbs and cover glass periodically. I'm not sure about wasted spectra when comparing one type of bulb to another. I do not pretend to be a lighting engineer, but neither am I totally uninformed. There are many kinds of flourescents, and a variety of MH bulbs as well. I am also not confident that we absolutely know, in terms of the needs of reef animals, what is "wasted" and what is not.

I am not really attacking metal halide lighting. I think nothing looks quite as spectacular over a reef tank, or is as effective in deeper applications. I do think they require considerably more attention, and have a few safety drawbacks, particularly around pets, small kids, etc. I was responding, in this string, to someone who had already ordered (it seems) a VHO system that is quite powerful, and, I think, more than adequate for the application described.

I've kept reef animals for several decades, and have my own opinions about the art and science involved. It's mostly art. The simpler the better is what I have come to believe, and most of the cranked up "high tech" devices marketed for reef tanks can be safely removed and tossed in the trash. Most are anodynes sold to people who are having problems because they have not developed the skills and the art of aquarium keeping. They run into problems, and are convinced that some gadget is all they need to set things right. An aquarium well stocked with healthy live rock will stabilize its own dynamic balances if the aquarist does not over meddle, and has developed a good skill level. But that is another topic.