Lighting choice AND BALLAST. SPS

[Reel North]

I'm having an issue with my par. I have 6 mo old 250 w radiums, and am running them on the silver pfo m80 that are also 6 months old. I found 4 new in the box.

I'm running them in lumenarc large reflectors, that are about 16" off the water to the bottom of the reflector.

I took at par reading, and it was under 290 about 8" under the water, and 117 on the sand.

I tried the radium 400 w in the same reflector, also on a silver pfo ballast, and par went to 400 in the same spot, up from 290.

This was a brand new, never used radium.

I've ordered a Hamilton Cozumel sun reflector (20x20") for the middle between the lights.

The 250w lamps don't reach to the middle of the lumenarc large reflectors, but the 400w does.

My rank is 72 L x 24" tall x 30" front to back.

I'm wondering what to do. I grow all sps.

Should I be changing everything to 400w, in the lumenarcs and the Cozumel, or change to the 3x Cozumel and keep running 250w with the m80s, or change everything to 400w.

I've read a ton, and now I'm torn.

 

[Reel North]

Bump

 

[Reel North]

I'm shocked there are no comments.

 

[sirreal63]

The bulb needs to align properly in the fixture, they do make adjustable sockets. If the bulb is off center it will change the way it reflects light, you should find a hotspot where the bulb is reflecting off one plane more than the others. I would try and find an adjustable length socket before anything else.

 

[kevin_e]

I think 250s are fine on a 25" tank, but I would definitely run a 3rd. Your setup is about as good as it gets, with the Lunarcs, radiums and M80. I would worry too much about readings, tbh.

 

[kevin_e]

The bulb needs to align properly in the fixture, they do make adjustable sockets. If the bulb is off center it will change the way it reflects light, you should find a hotspot where the bulb is reflecting off one plane more than the others. I would try and find an adjustable length socket before anything else.

Yes, this is true. Even a half inch can cause major differences.. I have adjustable sockets on mine.

 

[Reel North]

Where can I find those. It's always something, isn't it lol. I have a Hamilton Cozumel sun 20x20 coming at will fit in between the lumenarcs.

 

[sirreal63]

Google adjustable length mogul socket.

 

[C3hutson]

I had awful spread on my 250 watt radiums in lumenbrite minis until someone suggested to make sure they are centered. Par jumped up exponentially and spread evened out when I centered them in the fixture.

 

[Reel North]

I'm having a lot of trouble finding adjustable sockets. They DO sell an extension.

What I'm thinking I may install the Hamilton 20x20 that just came in, and check the par again in that fixture. If it works the way I hope, I'll build a light rack, and get 2 more, and call it a day. I'd much rather buy the fixtures, instead of buying new ballasts and jacking up my hydro bill with 400w.