Ati t5 lighting help

[ckcustomz]

Hey r2r...i need help... i was wondering... i went from a 3ft 6 bulb fixture to a 4ft 6 bulb fixture on a 75g 48 x 18d x 21h ... should it have to be hung alot higher due to higher wattage... some of my tips have been getting a little pale and white... all my sps is between 8”-15” below surface...the 4ft fixture was 10” above surface when i started noticing the tips... but i did have the 3ft fixture 8” above surface before i switched

 

[Reefltx]

Yeah, I would start off at 12” above the rim and work your way down slowly to 8”.

 

[Da8]

Guess so but you've just added length, no more bulbs so there is not much difference in par on the sps that were receiving direct light.

 

[homer1475]

Par should be the same, only difference is your now lighting the ends of your tank which you weren't before.

6 bulb T5 is a 6 bulb T5, you only added length not more par. Well techinically you added par, but only to the end of your tank that wasn't getting good par before.

 

[ckcustomz]

So the wattage wouldnt make a difference? Being that the 3ft bulb is 39w and a 4ft bulb is 54w.... im guess the wattage difference is because of length and power to light the bulb if im correct

 

[homer1475]

So the wattage wouldnt make a difference? Being that the 3ft bulb is 39w and a 4ft bulb is 54w.... im guess the wattage difference is because of length and power to light the bulb if im correct

Exactly as I understand it.

 

[Da8]

the PAR doesn't change.
It is just longer.

Obviously light now will affect a wider area, but will not add PAR or PUR to an already well lit area.

 

[Skynyrd Fish]

Just to be sure check your alk, po4, and no3.

 

[X-37B]

How old were the 36" bulbs?
I imagine the 48" ones were new?
Just shorten the time they are on and increase over a period of weeks.

 

[YankeeTankee]

It could just be growth, if you think its somehow related to the new lights/stress then all I can think of for a cause would be replacing really old bulbs with new ones. Just adding a longer fixture with the same number of bulbs should not change much. My honest opinion is it's something else but you could try 90s reefers suggestion if you think its the new bulbs.

 

[Reefltx]

Par should be the same, only difference is your now lighting the ends of your tank which you weren't before.

6 bulb T5 is a 6 bulb T5, you only added length not more par. Well techinically you added par, but only to the end of your tank that wasn't getting good par before.

Guess so but you've just added length, no more bulbs so there is not much difference in par on the sps that were receiving direct light.

If it’s a ATI fixture, the 48” will put out more par than the 36”.

 

[Da8]

If it’s a ATI fixture, the 48” will put out more par than the 36”.

Why?

It will get higher PAR to areas at the sides, but the centre will stay the same.

Or a I missing something?

 

[Reefltx]

Why?

It will get higher PAR to areas at the sides, but the centre will stay the same.

Or a I missing something?

It’s just something I’ve observed and I have experience with both. Currently using the 48” right now and I can tell you at the same distance, it will put out more par.

 

[Da8]

It’s just something I’ve observed and I have experience with both. Currently using the 48” right now and I can tell you at the same distance, it will put out more par.

Sure?
Meassured with a parmeter?

Would be very surprised (but yes, I can beleive it)

But common sense makes me think it's not possible.

 

[Reefltx]

It’s been awhile, but yes I used a par meter.
I think I was seeing about 50-100 more par with the 48” in the center.

 

[ckcustomz]

Just to be sure check your alk, po4, and no3.

Yea everything kinda went out of wak cause i did recently go straight sps and sold alot of lps and sps wasnt consuming the amount of alk my doser was putting im so i have reduced my doser to try to get it back to steady... and my phos was at zero which i finally got back up

 

[ckcustomz]

It’s been awhile, but yes I used a par meter.
I think I was seeing about 50-100 more par with the 48” in the center.

I was thinking the same that par would change cause if you wave in example 450 par in the center 6” wide on 36” fixture then you would think on a 48” fixture that would widen up to 10” 450 par and may even jump up in the 4” wide center area? Maybe?... they need cheaper par meters for us lol... i would even be on the forum right now lol... but you guys are big help

 

[Skynyrd Fish]

I’d pull the alk, ca dosing until your levels fall in line with your target. I also test alk everyday and keep a log.

 

[ckcustomz]

I’d pull the alk, ca dosing until your levels fall in line with your target. I also test alk everyday and keep a log.

Yea thats what i just did for the past few days to get an idea of how much is being used... thanks again

 

[Graffiti Spot]

I think the par changes because the 4’ fixture is the most efficient one if I remember correctly. I remember threads in the past where people said the 4’ fixture puts out slightly more par than the others. Not just on the ends of the tank but right in the middle. Could be wrong but you could do a few searches to confirm.