Par reading for T5

[marvelousone]

What is the Par reading I should get with T5 to grow SPS's. What would be the max and min. I have a 80w 8 bulb. check my par and at the top water level I had a reading 299. close to sand was 235. That was in the center of tank and fixture. On the sides at top was 275 and at sand 209. I am having problems growing SPS's so making sure it is not lighting. I see where some say you need a par of 400 or more.

 

[Crabs McJones]

What is the Par reading I should get with T5 to grow SPS's. What would be the max and min. I have a 80w 8 bulb. check my par and at the top water level I had a reading 299. close to sand was 235. That was in the center of tank and fixture. On the sides at top was 275 and at sand 209. I am having problems growing SPS's so making sure it is not lighting. I see where some say you need a par of 400 or more.

For SPS you want par of 250-350, however that's not to say that SPS won't grow in 200 par. You sound pretty covered with the numbers you're getting now.

 

[madweazl]

What is the Par reading I should get with T5 to grow SPS's. What would be the max and min. I have a 80w 8 bulb. check my par and at the top water level I had a reading 299. close to sand was 235. That was in the center of tank and fixture. On the sides at top was 275 and at sand 209. I am having problems growing SPS's so making sure it is not lighting. I see where some say you need a par of 400 or more.

There is no way eight 80w T5s are only producing 299 PAR near the top of the tank. I'd look into whatever it is that you're using to measure with.

Two 54w T5s over my tank produce 130 PAR eight inches below the surface.

 

[Crabs McJones]

How far off the waters surface do you have the lights mounted?

What is the Par reading I should get with T5 to grow SPS's. What would be the max and min. I have a 80w 8 bulb. check my par and at the top water level I had a reading 299. close to sand was 235. That was in the center of tank and fixture. On the sides at top was 275 and at sand 209. I am having problems growing SPS's so making sure it is not lighting. I see where some say you need a par of 400 or more.

 

[markalot]

How high is the light above water level?

What bulbs are you using?

What fixture?

As said above, 250 to 350 would be perfect but if you are running an ATI fixture with the fan set to 9 volts you should be getting at least 450 just below the water surface and 300 near the sandbed assuming the light is 3 feet above the waterline.

 

[bubbaque]

Here is a great video on par with the ATI t5 fixture.

 

[marvelousone]

There is no way eight 80w T5s are only producing 299 PAR near the top of the tank. I'd look into whatever it is that you're using to measure with.

Two 54w T5s over my tank produce 130 PAR eight inches below the surface.

lfs had a par meter. I don't know what brand it was.

 

[marvelousone]

How far off the waters surface do you have the lights mounted?

9 inches from top of water

 

[Crabs McJones]

9 inches from top of water

I'm going to have to agree with @madweazl par should be much higher. What are you using to take your par measurements

 

[marvelousone]

How high is the light above water level?

What bulbs are you using?

What fixture?

As said above, 250 to 350 would be perfect but if you are running an ATI fixture with the fan set to 9 volts you should be getting at least 450 just below the water surface and 300 near the sandbed assuming the light is 3 feet above the waterline.

The light fixture is 9 inches from top of water. It is ati with 3 fans. idk about 9 volts. I have ati bulbs 2-coral plus 1- purple plus 2- aquablue and 3-blue plus. The bulbs are 6-7 months old.

 

[marvelousone]

I'm going to have to agree with @madweazl par should be much higher. What are you using to take your par measurements

my lfs came and used a par meter they us. Idk brand or anything about it. That was the readings he gave me. I watched him do it.

 

[bubbaque]

If it is an ATI fixture than it definitely has higher par than that meter you used showed. Something has to be wrong with the par meter.

 

[x2uranium]

Nice vid bubbaque. I had converted my t5 8 bulb amazon grow light to icecap ballasts three weeks ago and torched two corals 12" below the surface. I forgot how powerful T5 / icecap combo was.

 

[Crabs McJones]

If it is an ATI fixture than it definitely has higher par than you that meter you used showed. Something has to be wrong with the par meter.

Yeah, something seems off...

 

[Anirban]

If the bulbs are already 6-7 months old then its possible that the PAR is possibly that low. But 200 is still good enough to grow things. You need to change bulbs slowly to bring up the PAR.

 

[Mr.Fishtank]

I have the same fixture. 11 inch's off the tank and I get about 625 at the water level. Half way down is 380. When I was running it closer I was getting almost 700 top and 440 middle. The par meter you borrowed isn't accurate.
If the room your tank is in stays cool 70-72 then I would run the fan speed at 4.5-6v. Higher then 72 just keep it at 7.5-9v.

 

[bubbaque]

If the bulbs are already 6-7 months old then its possible that the PAR is possibly that low. But 200 is still good enough to grow things. You need to change bulbs slowly to bring up the PAR.

BRS put out a video today and it showed par doesn’t really drop much over a year for t5’s. Ryan said he would no longer change bulbs at one year.

 

[Anirban]

BRS put out a video today and it showed par doesn’t really drop much over a year for t5’s. Ryan said he would no longer change bulbs at one year.

Thats nice to know. So, the only thing to consider now is change in spectrum overtime for fuller spectrum bulbs. Lol, now we can save some money too.

 

[marvelousone]

I have the same fixture. 11 inch's off the tank and I get about 625 at the water level. Half way down is 380. When I was running it closer I was getting almost 700 top and 440 middle. The par meter you borrowed isn't accurate.
If the room your tank is in stays cool 70-72 then I would run the fan speed at 4.5-6v. Higher then 72 just keep it at 7.5-9v.

So how do you change the fan speed.

 

[x2uranium]

In the video they show the switch is on the power plug.