Lighting question

[noxiousdog]

I'm pretty sure I have plenty of light at 7x80w t-5's, but I'm not sure how long I should be keeping each of the timers on.

The pride of my tank is this crocea:


Does the way he's displaying mean he wants more light, or that he's healthy?

[mbbuna]

how far from the lights is the clam?

i think i saw in another post of yours that your t-5 dont have individual reflectors, is this right?

[a4twenty]

if you don't have the individual reflectors i would suggest that you get them. to me it looks like your clam is reaching for more light. you might want to move him up a little higher in the tank. where is he now and how deep is your tank?

oooppss didn't answer about the timers. i keep mine on for 10 hrs, a lot of people will tack on 1 hour of actinics only to the beginning and end of the day.

[noxiousdog]

He's about 14" down, and yes, I have individual reflectors.

I'll check my timers tonight. They are on a 3 ballasts in a 3, 3, 1 setup.

[duds]

he needs to be moved up, 14" down is way too far down
Duds

[Peabody]

Agreed...he's asking for more light with that hyper-extension of his mantle

[noxiousdog]

Timers are as follows:

T1 - On sunup to sundown (plus 1 hour)
T2 - 6 hours
T3 - 6:30 hours.

All are 80W bulbs
t1- Pure Actinic
t2 - Midday, Aquablue, blue+
t3 - Pure act, Aquablue, blue +

[noxiousdog]

I went ahead and added a couple hours on timer 2 and 3.

Thanks for the advice.

[freddie40]

14" is not too far down in the tank for a clam with as much light as your tank has. Jeez, I just hate it when people who have never had T5's give advice. On my 75 with 6x54 watt pf T5 I get a par reading of 160. If tou were to use 2x250 watts of MH you would get a reading of about 130.

Dave

BTW: I have 3 Croceas living on the sand in my 75.

[a4twenty]

Originally posted by freddie40
14" is not too far down in the tank for a clam with as much light as your tank has. Jeez, I just hate it when people who have never had T5's give advice. On my 75 with 6x54 watt pf T5 I get a par reading of 160. If tou were to use 2x250 watts of MH you would get a reading of about 130.

Dave

BTW: I have 3 Croceas living on the sand in my 75.

how do you know which of us has had or currently have t5's and which haven't?

i don't think anyone was giving that advice based on his light fixture but more from looking at the picture. if you look back up at his original post that is exactly what he has asked for.

[critterkeeper]

Freddie, where'd you get those PAR numbers? I can't find much (well just about none) "real" data as far as PAR goes for T5s, and that sounds way too low for 250s.

This article shows numbers better than that for 175s...

http://reefkeeping.com/issues/2006-10/bp/index.php

[noxiousdog]

i don't think anyone was giving that advice based on his light fixture but more from looking at the picture. if you look back up at his original post that is exactly what he has asked for.

Absolutely. It doesn't matter how much light you -can- put out if you're not actually running it enough.

I'm sure that if I went 12 hours with all that light it would be way too much. I just need to find out where the sweet spot is.

[The Grim Reefer]

You have more than enough light for a clam or anything else you want to raise 14" down. You using Ice Cap ballasts on the T5's?

[noxiousdog]

Yes. the 660s. The single is on a Universal Lighting ballast.

[The Grim Reefer]

You have a ton of light. Easily equal to most 250 watt halides assuming you have your lamps mounted within 4 or 5 inches of the water.

[noxiousdog]

They are.

How often would you run them?

[The Grim Reefer]

I would run Blue/Actinics 12 hours and daylights 10

[noxiousdog]

thanks.

[critterkeeper]

Again I ask - where are you folks coming up with the idea that T5 outperform a 250w MH bulb.

Anyone???

[The Grim Reefer]

Having ran both T5's and Metal halides over the same tank and measured the PAR of both.

3 14K DE halides with PC Actinics = 95 PAR at the sandbed.

6x80 watt T5's running 3 blues (not even the better output Blue Plus) 1 Daylight and 2 Aquablues= 145 PAR at the sandbed.

[jmaneyapanda]

Hey grim- what were the specs of the lights and tank. did you test them the same day? How old were the bulbs? what ballast? etc etc etc???

[The Grim Reefer]

Tank was a 125, 72x18x23.5 tall. Sensor was 18.5 inches below the water surface. Halides were about 7" above the surface of the water. Halides were ran on EVC electronic ballasts with 14K lamps. Lamps were new. 10K lamps did 120 or so new. The 80 watt T5 lamps were from a few weeks to several months old when I measured them. No, they weren't checked on the same day (except for a 4x54 watt Ice Cap system which put 183 to the sandbed on a day the halides were doing in the 80's).

[jmaneyapanda]

What brand meter did you use? Those were 250 watt MH, right? How long apart were the readings taken? Was it on the same body of water? Same filtration/conditions? How about reflectors?Sorry for all the questions, but I am trying to equalize the parameters.

Our reef club here in Atlanta "rents" out their PAR meter so that members can check their lights. They are hoping to amass a number of measurements, including many I have asked you, and create a sort of reference chart.

[The Grim Reefer]

The halide reflectors werent the best but the UV shield was some kind of low lead glass that only decreased the light output by around 11%. The glass on most UV sheilds cut 18 to 22%,

The water parameters were pretty much unchanged. I had T5's and changed to halides and went back to T5's again. The T5's had similar readings both before and after the halides.

The meter is the Apogee QMSS with the remote sensor, www.apogee-inst.com

[jmaneyapanda]

thanks.