MH Question

Saltine · Nov 23, 2016

I'm currently running a 150w MH (20k Radium Bulb, double ended) T5 combo (4 24" T5's). A 36" dual 250W MH has come up for sale near me, and I would really like the additional MH coverage to reduce some shading/shadow. But I am in LOVE with the double ended 20k radium bulb, from what I've read, it's nothing like other 20k bulbs. I've put a picture of the two ballasts this fixture comes with below, what bulb would be like the 20k radium? I'm also running a 24" XHO Reefbrite strip that I would continue to run with this new light. Thoughts on switch from a MH/T5 combo to this just MH and LED? My T5's only put out 150 par to my SPS when they are on by themselves, and those are the top SPS, lower is 100-.

Thanks,
Salt

ksc · Nov 23, 2016

Why not just run a 250watt Radium? The reflector will make a huge difference in the amount of light the system puts out. If that's an old fixture just get a couple of new reflectors and retrofit the lights.

Saltine · Nov 23, 2016

ksc said:
Why not just run a 250watt Radium? The reflector will make a huge difference in the amount of light the system puts out. If that's an old fixture just get a couple of new reflectors and retrofit the lights.

My current combo fixture has built in ballasts so I can't upgrade to a higher wattage bulb. Also I don't think radium is selling double ended bulbs anymore.

Thanks,
Salt

ksc · Nov 23, 2016

The 150 Radium isn't the best looking bulb imo. The 250 is much nicer. That said, a pair of 150' s would do a good job lighting your tank. 250's would be a little overkill. MH setups are a dime a dozen right now. Decide what you want and buy it, don't settle on something you don't want.

Saltine · Nov 23, 2016

ksc said:
The 150 Radium isn't the best looking bulb imo. The 250 is much nicer. That said, a pair of 150' s would do a good job lighting your tank. 250's would be a little overkill. MH setups are a dime a dozen right now. Decide what you want and buy it, don't settle on something you don't want.

Thanks! Agreed I would prefer two 150w not 250w with only 24" deep.

Thanks,
Salt

mcarroll · Nov 24, 2016

I think you can make 24" work with 250 watt bulbs, but use a light meter before and during rehanging your lights to get the intensity right.

That said, I don't think those ballasts would do well on the Radiums, which run hotter than the nominal wattage.

Same for the 150's. But not the 400's....they run cooler.

This is why some folks think certain Radium bulbs don't look as good as other ones. (Looking at you @ksc! All Radium bulbs are beautiful!) :D ;)

If you run Radiums on their ideal ballasts, they all look pretty similar.

Going from memory (so someone correct me if I've misplaced some details!), but I think the deal was if you ran them hotter (higher watts) they'd get more white and less blue.....and hotter was more or less preferred.

150 watt bulbs were really run at 170 watts or 180 watts.
250 watt bulbs were really run at about 280 watts.
400 watt bulbs were the oddball "energy saver" designed to run at 360 watts.

So the smaller bulbs would run "too blue" on nominal ballasts that would actually limit them to 150 watts and 250 watts respectively.

In contrast, the 400 would run ideally on a nominally 400w ballast, since that was "hot" for that bulb.