Metal Halide for Planted Tank

[Sneakerpimp]

I ran into a problem getting the led I wanted and realised I have a $400 1000 watt dimmable ballist and lamp in storage. I would just need a bulb and I could start up the tank once it's cycled. Could even get a jump start growing out some beautiful high-light plants. Tank is 30 gallons and 18" tall.

What type of bulb would be appropriate?

Would I get away with it dosing excel?

 

[tanker]

You would need a bulb in the 6500K to 10,000K range. IMO, just dosing Excel would not do, and may even be bad if you are relying on just excel.

 

[Sneakerpimp]

You would need a bulb in the 6500K to 10,000K range. IMO, just dosing Excel would not do, and may even be bad if you are relying on just excel.

6500k bulbs would probably be more suitable for aquatic plants(10k for coral?). They are 250 watts and I could dim them to as low as 50%.
Seems like 250w 6500k's online are pretty cheap didnt want to spend 80+ on a bulb.

 

[jpappy789]

10,000 K can work just as well for plants, tends to be more of an individual preference in that range. Sometimes the lower end looks to yellow for people's taste; sometimes the other end is too blue-ish (I've always liked a mixture when I can).

I'd be most worried about heat as MH are notorious for their output. Would you be able to raise or hang the light over the tank just in case?

I'd also agree that it may be too much for Excel alone, but dimming may help.

 

[FreshyFresh]

I never knew MH fixtures could be had dimmable!

Regardless, even if you were able to dim a 250w MH half way, that's still a lot of heat on a small tank like said.

 

[Sneakerpimp]

10,000 K can work just as well for plants, tends to be more of an individual preference in that range. Sometimes the lower end looks to yellow for people's taste; sometimes the other end is too blue-ish (I've always liked a mixture when I can).

I'd be most worried about heat as MH are notorious for their output. Would you be able to raise or hang the light over the tank just in case?

I'd also agree that it may be too much for Excel alone, but dimming may help.

Alright, thanks. I was browsing other forums that came up on google and this guy said 10000k will work for some fw plants but is mainly a spectrum for coral. This doesn't seem right to me. Wouldn't most high light green plants do better with the higher white/blue spectrum?

Kind of off topic, but what lighting is best for those nice looking red plants?

 

[Sneakerpimp]

I never knew MH fixtures could be had dimmable!

Regardless, even if you were able to dim a 250w MH half way, that's still a lot of heat on a small tank like said.

Easily fixed with one of my summer fans!

Yeah, it's a pretty nice BC ballast 100/75/50% modes. I think the company isn't around anymore, there was a defect in many of the first units they launched. I got lucky though. Another Canadian company bites the dust...

 

[jpappy789]

Alright, thanks. I was browsing other forums that came up on google and this guy said 10000k will work for some fw plants but is mainly a spectrum for coral. This doesn't seem right to me. Wouldn't most high light green plants do better with the higher white/blue spectrum?

Kind of off topic, but what lighting is best for those nice looking red plants?

The color/K rating isn't necessarily the spectral output as it's based off of what the human eye perceives (and most of the blue needed for corals comes from actinics, I believe). I've never had a problem using it but there are a lot of plants I've never attempted to keep...

Some bulb brands will publish those stats, in which case you'd be best finding something with peaks near the blue and red wavelengths. Otherwise, anything marketed as "for plants" is probably fine (not sure what's still out there for MH though since it's hardly used anymore).

For red plants, the red color may not be seen well without those wavelengths to reflect. And enough Fe is generally recommended as well.