fishyspots

Aquarium size:
46 bowfront (36x16x21)

Type of light fixture AND reflector:
Standard Marineland fluorescent fixture on one tank
Coralife T5 fixture on the other

Number of lamps, bulbs, or tubes, and wattage:
one Marineland Natural Daylight bulb in the standard fixture (couldn't see a wattage)
Coralife 6700k and Colormax bulbs in the Coralife T5 fixture

Age of lamps, bulbs, or tubes:
3-4 months on all

Distance from light fixture to substrate:
19" on the standard fixture
17" on the Coralife

PAR VALUES MEASURED AT SUBSTRATE:
8 on the standard fixture at substrate, 23 mid column
7 on the Coralife fixture at substrate, 18 mid column

Comments: I found it VERY interesting that the stock fluorescent bulb gave HIGHER readings than the Coralife double bulbs, especially when it sits further from the substrate!! So much for buying the more expensive special plant light fixture

fishyspots

Aquarium size:
standard 55 gallon (48x12x21)

Type of light fixture AND reflector:
GLO T5HO 48"

Number of lamps, bulbs, or tubes, and wattage:
one Coralife 6700k 54W

Age of lamps, bulbs, or tubes:
3 mos

Distance from light fixture to substrate:
19"

PAR VALUES MEASURED AT SUBSTRATE:
15
45 at mid column

Comments: Another tank that I expected higher readings on......

fishyspots

Aquarium size:
90 gallon (48x18x22)

Type of light fixture AND reflector:
two shoplights with clear plastic splash covers from Home Depot

Number of lamps, bulbs, or tubes, and wattage:
four Phillips 32W 6500k daylight bulbs from Home Depot

Age of lamps, bulbs, or tubes:
1 month

Distance from light fixture to substrate:
21"

PAR VALUES MEASURED AT SUBSTRATE:
28
60 at mid column

Comments: Does this sound right to everyone? Really expected higher readings with that many watts on top of the tank......

Michael

Great information!

A question about the Marineland fixture on your bowfront: what size tube is in it? Fluorescent tubes are measured both by length and diameter. A T5 tube is 5/8" in diameter, T8 is 1" (8/8"), T 12 is 1 1/2" (12/8"), etc. Yes, it is the most inane system they could come up with.

On your last tank, this may be a case where the reflectors and splash guards are reducing the light output. Shop lights have notoriously poor reflectors (almost as bad as those mylar things in the Coralife fixtures) and the splash guards may be filtering out some useful light. I agree, the light levels on that tank are disappointing. Could you remove the splash guard and remeasure the PAR?

fishyspots

The Marineland fixture is a T8. Sorry, forgot to put that in there!
Will get additional readings on the 90g tomorrow as the timer is already off tonight and I'm too lazy to turn it back on.....

Michael

One other thing I forgot to mention, I did some side by side measurements of Coralife 6700K and Colormax tubes at a display tank I set up at a LFS. The Colormax tubes produce almost no PAR at all--it was almost like the fixture was turned off.

So in your 2 tube T5 fixture, if you replace the Colormax tube with something else, even a generic "daylight" tube from the hardware store, you might double the effective light on that tank.

fishyspots

I pulled the reflectors off the shoplights today and got higher readings. With reflectors most of them were in the upper 20s/mid 30s and the same spots without the reflectors ran mid 30s/upper 40s. Still lower than I had hoped for but some improved.....

fishyjoe24

The t5 n.o. Fixtures don't have a reflector it's basiclly
Gray paper. I've took one apart because the reflectors have gone bad.
The Hagen glo fixture only have decent reflectors..
I like highly polished german reflectors and Gisemann mid day bulbs.

BenChod

Aquarium size:
Standard 75 gallon (48x18x21)

Type of light fixture AND reflector:
Standard 48 inch T8 fixture with

Number of lamps, bulbs, or tubes, and wattage:
48" 32 watts GE 6500K from Lowe's....total 64 watts


Age of lamps, bulbs, or tubes:
2 weeks

Distance from light fixture to substrate:
18"

PAR VALUES MEASURED AT SUBSTRATE:
28
40 at mid column
160 at surface

Comments: The reading is direct light as no glass top is used. The reading above was with tannin in the water. I did a 50% water change the the reading improved to 34-38 at substrate and in 50's in the mid column

Also The fixture was modified by use of foil tape to create reflector in the fixture as there were no reflectors.

BenChod

Aquarium size:
240 gallon (96x24x24)

Type of light fixture AND reflector:
Coralife NO 48 inch T5 fixture

Number of lamps, bulbs, or tubes, and wattage:
48" 28 watts 4100k from home depot and 10000K

Age of lamps, bulbs, or tubes:
2 weeks on 4100K and 1.5 months on 10,000K

Distance from light fixture to substrate:
22 to 23"

PAR VALUES MEASURED AT SUBSTRATE:
22 at substrate
26 at 18" from light fixture
33 at 12" from light fixture
240 at surface

Comments: The reading is direct light as no glass top is used.The fixture was modified by use of foil tape to create or improve the reflector.