150 gal.--30" deep

Szkalak

Lifetime Charter Member
Lifetime Member
May 21, 2010
18
0
1
All:

I'd appreciate your input here. I have a deep tank that measures about 28" deep from substrate to surface + or - 1" taking water evap into consideration. Currently running a Teklight 48" x 6 bulbs. I run only four bulbs (6500K) at about 6.5" from water surface. After reading the articles concerning PAR values by the various plant wizards in the forum, I am currently wondering if my current light setup needs to be tweeked. Specifically-is my light too close to the water surface, or, perhaps not close enough? The growth of my plants is currently rather minimal, but overall color and appearance is pretty good. Pressurized Co2 via needle wheel is injected into the tank by spray bar near the bottom of the tank @ 4bps. I follow typical recommended EI dosing values and WC 2x week. I realize that each system is unique, but I'd appreaciate your thoughts and comments on where you think the starting point should be for this light when considering the depth of the tank and how many bulbs you would start out with. My current approach needs some intervention. Thanks.

Best Regards,
Justin Szkalak
 

dutchy

Plant Guru Team
Lifetime Member
Jul 6, 2009
2,280
4
36
61
The Netherlands
I found out that with my 4 rows of T5's every 4 inch in depth reduces the PAR around 10 micromols. When used with reflectors, they give 90 micromols at the substrate at a depth of 23 inch (substrate to bulb)
You have 34,5 inch (28 + 6,5) The difference is 11,5 inch, let 's say 12. That means a reduction of another 30 micromols, which would give you 60 micromols at the substrate. That's a good value which I would only change (less) if there were any algae / CO2 issues.

These numbers are only valid when using reflectors.

regards,
dutchy
 

shoggoth43

Lifetime Charter Member
Lifetime Member
Jan 15, 2009
1,092
11
38
It would sound that you're right around where you want to be. Growth is slow/minimal and no algae right? How long has it been running? I prefer to have more distance between light and surface just to make it easier to reach in, but that's not a typical concern for most people. If it's only been a few weeks, then I'd leave it be. You may find things pick up after a few weeks and the plants adjust to the nutrient/CO2 levels. If it's been a several weeks now, then maybe you could tweak a few things if you want faster growth, but otherwise it sounds as though you're on target.

-
S
 

Szkalak

Lifetime Charter Member
Lifetime Member
May 21, 2010
18
0
1
Thanks for the feedback guys, it's most appreciated.

Best Regards,
Justin Szkalak