Need help with light upgrade

[ahochan]

I'm looking for a light upgrade for my 60 cm tank.
My current light is a 36W power compact with one double-tube (10.000k/blue).

The corals in my tank are:
1 Yellow polyp coral, 1 Pachyclavularia spp. (Green star coral), 1 Euphylla (torch coral) and 1 Discosoma spp. (Mushroom polyp)

They seem to be doing well, but I think a light upgrade will be beneficial for their prolonged health.

I'm in Japan, and the selection of florescent fixtures is not so great. There's plenty of MH fixtures available.

I've found three options that seem promising:

- 36W x 2 power compact fixture (same as I have, but with two tubes) ( http://www.aqua-system.net/llumi_twin/)
- 55W x 1 power compact fixture (http://www.aqua-system.net/llumi_ion/)
- 150 W 20.000 K MH fixture (http://www.aqua-system.net/llumi_mone/)

Any thoughts? I'm a bit unsure about what counts as too much and what is too little.

 

[lando]

I would go for the 2x36watt CF if you want to stick with softies and LPS corals. If you would like to house clams or SPS corals the the MH would be a good option. Make sure you read the "Photo-acclimation" article in the ARTICLES section at the top of the page.

 

[MT79]

Any thoughts? I'm a bit unsure about what counts as too much and what is too little.

I would say 3 WPG is a good minimal number. WPG is not the greatest way of measuring light, but it works OK in determining minimum amounts necessary IMO. What you currently house are low-moderate light corals. As far as too much goes, that depends on what you plan on keeping in the future, as Lando pointed out.
Any VHO sytems available? I like them better than PC, I think many people would agree.

 

[ahochan]

Minimal wattage works out to 78W if I count sump volume, 63W if not. So basically, the 2x36W fixture is just enough or a bit to small.

I plan on sticking with softies for now, I don't think my tank size or husbandry skills are up to SPS corals yet. That said, I'd like to stay future-proof, so I won't rule out either SPS or a clam completely.

If I get the MH fixture, would I end up hurting my current corals instead of helping them? (my tank is 30 cm deep) The MH I'm looking at has an extendable arm, so I could extend the arm to put the light farther away from the tank. Would that help? The MH is about twice the price of the PC, but the PC fixture is basically 60 cm only, so if I ever upgrade my tank it will be useless.

As for photo-acclimation, I currently have the lights on for 12 hours. So if I go for MH, I should set this to 4 hours, and increase by 1 hour a week until I reach, what 10 hours? 12 hours? I guess I could start a bit higher with the PC fixture, say 6-8 hours?

Finally, any tips on how to tell VHO from PC?

 

[tecwzrd]

MH will provide more options in the future and raising it will reduce the intensity some but you will still need to photo acclimate your current corals to the more intense light as you already mentioned and 4 hours increasing 1 hour weekly is conservative and can probably be increased 1 hour every 3-4 days IMO.

I assume you are looking at 150W MH pendents.

PC bulbs typically have Panasonic style “Square Pin” socket (GY10Q)

or German style straight pin (GY10Q)

and VHO bulbs have a Bi-Pin Base like regular florescent bulbs.

 

[melosu58]

Moved to General hardware and equipment discussion. As stated above it depends what type corals you want to have. As Mike stated the VHO would be better than the PC`s IMO.

 

[ahochan]

Thanks for the pictures, very helpful!

Am I right in assuming that VHO fixtures will usually come with an external ballast?

The MH fixture I'm looking at is a 150W "crane" type that attaches to the back wall of the tank.

As I mentioned, I will probably stick with softies for now, but I'd like to go for a lightning system where I can put in more light-demanding corals as well. So basically, if I can find a good VHO fixture I'll go for that, otherwise I'll go for the MH.

 

[MT79]

Am I right in assuming that VHO fixtures will usually come with an external ballast?

Yes.

So if I go for MH, I should set this to 4 hours, and increase by 1 hour a week until I reach, what 10 hours? 12 hours? I

8-10 hours is normal. I much prefer using the screen method, possibly in conjunction w/ a shorter photoperiod. MH light is much more intense than fluorescent. Corals can burn in only a couple hours under them, unless slowly acclimated. Placing a few layers of screening over the tank reduces the intensity of the light. Removing one layer of screen every week or two will allow the coral to slowly acclimate to the brighter light.

but I'd like to go for a lightning system where I can put in more light-demanding corals as well. So basically, if I can find a good VHO fixture I'll go for that, otherwise I'll go for the MH.

MH will provide the most light. If you plan on keeping high light coral in the future, I recommend going w/ MH. Good luck

 

[melosu58]

Am I right in assuming that VHO fixtures will usually come with an external ballast?

yes this is true. Mine did.

 

[ahochan]

If I go for the MH fixture, it will be MH only with no supplemental florescent tube. Will a 8-10 hours daily photoperiod still be enough then?

 

[tecwzrd]

Yes, due to the intense MH light 8-10 hours is plenty. You probably will want a higher kelvin rated bulb i.e. 12k-14K if only going with MH. Checkout this link for color comparisons.

 

[ahochan]

The MH fixture I'm thinking of buying comes with a choice of 10k and 20k. I'll probably go for the 20k, although it might be a bit on the blue side for my taste