20,000k MH and Actinics question

[ai-reefer]

Currently i have the lights in the following order from back to front


10,000k T5 HO
Actinic T5 HO
2 x 14000K MH (250W)
15,000k T5 HO
Actinic T5 HO

I want to change this to

Actinic T5 HO
10,000k T5 HO
2 x 20,000K MH
10,000k T5 HO
Actinic T5 HO

or


Actinic T5 HO
10,000k T5 HO
2 x 20,000K MH
15,000k T5 HO
Actinic T5 HO


which would be better for a light blue color. Currently it looks very white.

I guess the real question i have is, can you substitute 20,000K MH for Actinics?

 

[waynesworld]

Pers I would do
act
15k
MH
15k
act
The act I would use is the geisman true they have purple in it and the 20k mh will have a lot of blue. If you still wanted more blue I would change one of the 15k to a blue

 

[DMBillies]

I think it might help if you listed the brand and name of the bulbs. It seems, to me anyway, that T5's vary even more than MH when it comes to the bulb actually comparing to the color temperature that they are supposed to (this could be just because I know more about T5).

Usually I would say most people are going to use halides to push the lowest K values and use T5's to supplement the blue. I'd actually do some research to see if that really makes the most sense. I mean in terms of the tank coverage you'd like (will you have big darks spots in bad places if you use the halides for the main light source) and whether or not the light output will be most effective that way. In general lower K bulbs have higher PAR values (photosynthetically active radiation), so as you add more actinic you'll lose PAR. You might lose more PAR by going with 20,000K MH's as opposed to just swapping out a T5 or two with a higher K bulb. The only source of information about what effect that change might have that I can think of is Sanjay's lighting guide and I'm not positive it will have the info you need.

If you do change the T5's you'll at least have better control over how much blue you get. I might just get an actinic plus and replace either of the 10,000 or 15,000K bulbs. If that's not enough, buy another actinic plus and put it in the other one so you have the halides and then all actinics.

 

[ai-reefer]

<a href=showthread.php?s=&postid=14729960#post14729960 target=_blank>Originally posted</a> by DMBillies
I think it might help if you listed the brand and name of the bulbs. It seems, to me anyway, that T5's vary even more than MH when it comes to the bulb actually comparing to the color temperature that they are supposed to (this could be just because I know more about T5).

Usually I would say most people are going to use halides to push the lowest K values and use T5's to supplement the blue. I'd actually do some research to see if that really makes the most sense. I mean in terms of the tank coverage you'd like (will you have big darks spots in bad places if you use the halides for the main light source) and whether or not the light output will be most effective that way. In general lower K bulbs have higher PAR values (photosynthetically active radiation), so as you add more actinic you'll lose PAR. You might lose more PAR by going with 20,000K MH's as opposed to just swapping out a T5 or two with a higher K bulb. The only source of information about what effect that change might have that I can think of is Sanjay's lighting guide and I'm not positive it will have the info you need.

If you do change the T5's you'll at least have better control over how much blue you get. I might just get an actinic plus and replace either of the 10,000 or 15,000K bulbs. If that's not enough, buy another actinic plus and put it in the other one so you have the halides and then all actinics.

I see what you're saying. I usually have my T5 lights on for 10 hours and MH for 6.

So when the MH are off, the 2 x 10,000k T5's in the center and 2 x Actinics on the outer region that should give the coral plenty of light in the right spectrum to grow right? If the Par values are high for 4 hours, is that a good amount of time?

I think you are right about people using lower k in the primary MH bulbs and adding actinics. I wanted to try it the other way around since T5 stay on more anyway

That was the idea behind my plan. What do you think?

<a href=showthread.php?s=&postid=14729760#post14729760 target=_blank>Originally posted</a> by waynesworld
Pers I would do
act
15k
MH
15k
act
The act I would use is the geisman true they have purple in it and the 20k mh will have a lot of blue. If you still wanted more blue I would change one of the 15k to a blue

Thats an interesting setup. Thats probably the color im looking for.

 

[ai-reefer]

I think the T5's i have are

2-ATI Blue Plus,

1-UV Lighting 10000K AquaSun

1-15,000k Giessmann

 

[DMBillies]

Man, if I remember correctly, the aquasuns are really pink in color. That could singlehandedly be causing your tank to look on the "warmer" end of the color spectrum.

What size bulbs are you running? You might be able to just grab an older one (or a couple) from somebody and try out some different combos. If I can remember to do it tonight I'll dig in my attic for my old bulbs. You're free to borrow them if I still have them, just might have to wait until after the weekend to get them from me.