Building a seed and plant starting shelf

if you're a gardener, seed starting time is here and if you're like me you never have enough room to start everything. I don't have a ton of space indoors so a couple of years ago I decided to build something for just that purpose. I use heavy duty wire/chrome shelves available from a local DIY store along with fluorescent lights and seed heating mats where necessary. The shelves that come with the unit are 18"x48" which is almost the exact length of a standard 1020 seed flat (within 2 inches). They're wide enough to hold 4 flats on each shelf, so with the above parts you'll have enough to hold 12 total flats. With standard 72 cell starters trays, that's 864 seedlings!

Here's the parts list and retail pricing in the Chicago area:

QTY	ITEM	$ EA.	TOT. $
1	Wiretech 48x18x72 shelf	$59.98	$59.98
8	American Standard PES120ST12-1 Fixtures	$17.99	$143.92
8	Sylvania 6500K Daylight T12 fluorescent lights	$5.98	$47.84
8	Sylvania Gro lux T12 fluorescent lights	$5.98	$47.84
1	Analog Timer	$6.99	$6.99
2	6 Outlet power strips	$2.99	$5.98
		TOTAL:	$312.55

I attached the lighting fixture directly to the shelves using the chain that came with them; however I did cut them down in length to around 4 inches so they're closer to the shelf. It is possible using that method to hang them exactly at the height you want them above the seedlings.

Improvements on the original unit:

• A 5^th shelf that would add capacity for 4 additional flats.
  
• Seedling heating mats to the top most shelf.
  
• Tied off all the wiring nice and clean to the shelf frame using wire ties.
  
• Took the leftover lighting chain to hang yellow sticky traps on each level between the fixtures.
  

Planned improvements on the units:

• Cover the inside of the fluorescent fixtures with Mylar film to improve reflection.
  
• Test alternative bulbs to increase CRI and Kelvin.
  

I chose the fluorescent tubes about for a few reasons, first and foremost is cost. Given the number of bulbs I purchase yearly I needed to maximize growth against the raw cost. Also, I wanted to be able to easily find them at local DIY/hardware stores to avoid shipping cost and damage. I've been using fluorescent tubes for several years to start seedlings and I have found that if I alternate the 6500's and the Gro Lux tubes the plants receive a decent amount of light, the CRI is ok and the cost isn't that bad on a yearly basis.