Lighting an Aquarium with PAR instead of Watts

[tylergvolk]

I have 2 questions that I wold like to address. One the them everyone could benefit from and the other question is more specific to my setup.

I have a coralife 36" T5HO fixutre with 2 39w bulbs
1. 6,700K BULB
2. Colormax BULB

I currently have the fixture lifted 15 inches from the substrate which is about 40PAR; however, I read somewhere that the colormax bulbs don't provide as much PAR value as the regular 6,700K would. Is this true? Has anyone tested the colormax PAR values?

I also have a recessed canister in my ceiling that give off light to this tank. It is a single LED 13w 800lumes bulb about 32" from the substrate at the front of my tank. My question is, how much will this effect my PAR?

[Hoppy]

Someone can contribute information if they have the two bulbs and a PAR or lux meter. Just take light readings at various distances from the light, and report the readings here. Without that data one can only guess whether the two bulbs produce about the same PAR.

[tylergvolk]

Originally Posted by tylergvolk

I have 2 questions that I wold like to address. One the them everyone could benefit from and the other question is more specific to my setup.

I have a coralife 36" T5HO fixutre with 2 39w bulbs
1. 6,700K BULB
2. Colormax BULB

I currently have the fixture lifted 15 inches from the substrate which is about 40PAR; however, I read somewhere that the colormax bulbs don't provide as much PAR value as the regular 6,700K would. Is this true? Has anyone tested the colormax PAR values?

I also have a recessed canister in my ceiling that give off light to this tank. It is a single LED 13w 800lumes bulb about 32" from the substrate at the front of my tank. My question is, how much will this effect my PAR?

Read post number 61 & 66 from the following link:

http://www.aquaticplantcentral.com/f...lection-7.html

I wonder if this information is credible...

[Amandas tank]

I just finished reading through this thread and I want to thank you Hoppy and all those that have contributed. Now, if only I can wrap my mind around this and make sense of it I'd be well on my way

My tank is 48" x 18" x 24". Right now I have two 48" T8 bulbs that say nothing on them other than they are 40 watts each. They are pink and came with the tank (bought off craigslist). I also have two 36" T5 bulbs on the front side of the tank. Both are 39 watts one being 6500K and the other 10000K. I have no clue the PAR rating of any of them. I am concidering just starting over with new lights all together choosing something from the charts you have provided so the PAR is already pointed out for me. I do not use Co2 and don't plan to start. So, I definetely need to stick with low light.

If anyone of you reading this have a tank similar to mine without Co2, and your plants are doing great, please share with me what you are using. Hoppy, if you have a recommendation, I'd greatly appreciate it!

Thank you for your time and effort you've put into this thread and helping those of us that are at a loss in the lighting side of the hobby.

[Gold Finger]

Am in a similar situation as Amanda's Tank. Have four T8's on top of my 24"tall 80 gallon tank. It should be low light at ~40umol, I guess. I want to go up to medium at ~55umol since adding excel and ferts. Will be looking to get a double T5HO fixture with poor reflector and rest it right on top. No real question here. Thank to Hoppy, all my answers are out there.

[Sluggo]

Overwhelmed with info here. Looking to light a 38-gal with low-medium light. Tank is 20"H x 36"L x 12"W. I have a Coralife 2x96w PC fixture on hand, but the fan is noisy. There is a Current 3x39w T5HO available that is very affordable. Or, am I better off with something from Home Depot?

[Hoppy]

Originally Posted by tylergvolk

Read post number 61 & 66 from the following link:

http://www.aquaticplantcentral.com/f...lection-7.html

I wonder if this information is credible...

It would be interesting for someone to go through that whole thread and compile the data by manufacturer's lights. For example, I don't have any good data for the Coralife PC lights, and I noticed that there is some there, which supports my opinion that those lights are very poor ones.

[switch26]

I see the Aquatic Life 36'' T5HO fixture, but I have 2 bulbs instead of 4..

2, 39w bulbs, one 6000k and the other is a 650nm roseate, im thinking of replacing with 2 6500k bulbs for better plant growth..

Anyway, can anyone tell me what my readings would be for that fixture currently? I have a 30 gallon tank and my fixture is about 16 inches from my soil?

[Hoppy]

Originally Posted by switch26

I see the Aquatic Life 36'' T5HO fixture, but I have 2 bulbs instead of 4..

2, 39w bulbs, one 6000k and the other is a 650nm roseate, im thinking of replacing with 2 6500k bulbs for better plant growth..

Anyway, can anyone tell me what my readings would be for that fixture currently? I have a 30 gallon tank and my fixture is about 16 inches from my soil?

You should get about 70-75 micromols of PAR with that light, which I consider to be high light.

[switch26]

Thank you hoppy. Would that be the same even with the stock bulbs that I listed? Or if i got 2 new 39w 6500K bulbs?

Reason being is my growth is significantly slower with the stock bulbs than before when i used 2 flat coral life fixtures with very poor reflectors.

Although it was still 4 bulbs. and they were 6500k each, not HO

[jabba]

Tank: 55 gallon, 19 inch tall
Lights: 2x Hagen Power-Glo T5HO 18,000k, 2150 lumens, 233 lux
Light Distance: 24 inch

Ok from what I've read so far, I should be under 40 par. I couldn't find anyone with a par reader for me to measure so I was hoping anyone can confirm this? I was planning to move it up by 12 inches from the top but I'm afraid of losing too much par.

What kind of bulbs was used to test out the Hagen lights were used? was it the 6500k or the 18000k or it doesn't matter, all 54w are the same? I was hoping to achieve around 50 par but I guess it won't be possible unless I want to dish out money for new lights.

[Hoppy]

Those charts will give you approximate values for the PAR at the substrate, but if you want to really know what PAR you have with your tank and your bulbs and your light fixture, you have to measure it with a PAR meter.

There is still a lot to be learned, and probably un-learned about various lighting options. For example, what is the effect on PAR using various color temperature bulbs, or bulbs from various manufacturers, or year old bulbs vs new bulbs, etc. Also, do plants really respond the same to 50 micromols of PAR from a LED light made with cool white LEDs and one made with a mix of different colors? Any one with a PAR meter and enough interest can contribute a lot to our knowledge.

[AUvet14]

I have a GLA 36-L, same size as ADA Mini M, on the way. I am considering lighting options for it. I do plan to run CO2 with ferts. I am aiming for "high light". The fixtures I have pretty much narrowed it down to are the Archaea 27W Power Compact fixture and the 16'' Finnex Ray 2 DD LED fixture. Considering the size of the tank and what I want to grow (probably HC or glosso carpet and potentially some red stems), would both of these fixtures likely be sufficient?

[thegr8wendt]

Compare (2) 90 watt LED fixtures (180 watt total) to a hybrid fixture with (1) 150 watt Metal Halide & (1) 39 watt PC. (190 watts total). Will it actually cost less to run the LED lamps as opposed to the hybrid fixture with Metal Halide & PC lamps? Or is a watt a watt regardless of the source?

[kyleax1]

I have a 55 gallon tank and have 48" Nova Extreme 2xT5HO. When I bought it I thought I was getting the recommended light for medium light plants (2 wpg).

After continually fighting algae I started looking for answers and found that based on your par info that these are most likely considered high light for my tank.

I wanted to take one bulb out, but then realized it only works if I have 2 bulbs in.
If I take window screen and put a layer of it inside the light on the plastic slide out splash guard will that reduce the light enough to help keep the algae down but still be enough for all my plants on the bottom? The screen won't melt/burn will it?

I have dwarf sag that is finally starting to spread, but I'm sick of clipping bba and hair algae every day. I've already reduced my light period to 6 hours a day and its slowed down the algae, but has not stopped it.

I use diy co2, don't want pressurized co2 and is seachem fert dosing chart, but am soon hoping to switch to pps pro.