MH questions

[ahochan]

I asked some advice regarding upgrading my 36W PC lights (60 cm tank) a while back, but never got around to buying.

I currently have the choice between a 150W MH and a 70W MH (both are actinic and double-ended). What I want is basically to expand my future options a bit to perhaps include a bit more light-demanding corals (and perhaps a clam).

My corals are: Euphylla, mushrooms, green star polyp, pink tree coral (lemnalia?) Everything is doing well, except for the Euphylla which is slowly shrinking. I'm a bit worried that adding MH will cause the mushrooms to decline (they are growing rapidly in the current conditions). I'm thinking about adding a big centerpiece tree coral, and I guess that will benefit from stronger light.

I'd like some advice on the following:
- 70 W vs. 150 W (considering both the continued health of my current corals as well as future options)
- Acclimation and photoperiod for both options

 

[usmcmarc]

you definitely want to go with the 150w....especialy if you want a clam.

I went from 72w PC 10000K & 72w PC Actinic to a 150w HQI 14K and 72w PC Actinic.

Acclimation was done by placing 5 sheets of screen between the light and the tank, and removing 1 sheet per week.

 

[cmor1701d]

I currently have the choice between a 150W MH and a 70W MH (both are actinic and double-ended).

I've never heard of Actinic MH bulbs before. Do you mean 20k?

How big is your tank (gallons or litres)?
What are the tank dimensions (height is needed)?

How high above the tank are you going to hang the light?
If you have the option of changing the height and your tank is around 45cm - 50cm high then go with the 150w.

You can photo acclimate the tank by raising the light at first and thne lowering it a few cm every week. You could also use some screening material (5 sheets to start?), then remove 1 sheet a week.

 

[ahochan]

The tank is 60 cm x 30 cm (depth) x 45 cm (height). Its about 100 l including sump.

I'll need to buy a stand with the light, so I don't really know how high above the tank it will end up. Recommendations?

And yes, the bulb appears to be either 15k or 20k.

 

[cmor1701d]

I have no idea what fixtures are available in Japan. Some fixtures are designed to sit on top of the tank, hopefully on legs that raise the fixture several inches above the tank. Others are designed to hang from the ceiling.

Your existing corals like low to medium light. They will probably be ok if acclimated to the 70W. The 150w may be too much unless you can shade them. Of course, the 150 will let you keep just about any high light loving corals too.

With the 70 you can place more light demanding corals higher up in the tank.

Try to make a list of what you want to put in the tank and look at what each requires in the way of light, flow and feeding. That will help you answer which is better for your situation.

 

[ahochan]

Here's the specific light I'm considering:
http://www.aqute.co.jp/lineup/lineup_crystalshine.html

Stand:
http://www.aqute.co.jp/lineup/lineup_crystalarch.html

The mushrooms will be difficult to move, as they are basically growing everywhere on the LR, and are firmly attached.

As I mentioned, I want to add a big tree coral, and also perhaps a couple of more euphylla types (hammer coral perhaps). Also, I want a xenia. Apart from that I haven't really given it that much though yet. What I hope to achieve is a bit more leeway when selecting corals (currently I often find that when I see something I like it turns out that my lights are too weak).

I can live without the clam though... but would it be ok quite high up with the 70W?

 

[cmor1701d]

Interesting light fixture. The items you have and want to get should all be fine with 70w MH in that tank. A Derasa clam would probably be ok under that light too.

 

[ahochan]

Thanks for the tips.

One small thing... Will a Bubble Tip Anemone be ok with the 70W?

Tips for corals I will be able to keep with the 70W MH and not with my current 36W PC are also welcome

 

[Lance M.]

Yes. A bubble tip anemone would do well under 70 watts, even better under 150 watts. Your tank is about the size of a stand 20H, just a little taller.

I would be worried in such a small tank about the anemone being killed or killing the hammer/torch corals that you want to keep or already have, not to mention killing pretty much all the corals it comes into contact with in your tank. Depending on the aquascaping it can be done, but it would be short term because the anemone will grow, probably relatively fast, and they get big, it could easily take up one side of your tank.