There are a few alternatives for hydroponic lights there are florescent lights, high intensity discharge lights and light emitting diodes or LED lights. Among the three LED lights are the latest and are starting to gain much popularity. Although they cost more there are many benefits to using LED lights including efficiency, durability and reduced heat ideal for heat sensitive plants.

offer an ideal start up method for those new to hydroponic planting. They are easy to install and available in most hardware stores and gardening supply stores. The price initially is a bit high but considering the money that can be saved in electric bills it is worth it. In choosing LED lights, choose those with red or blue spectrum, these are more conducive to blooming and growing plants. White LED bulbs do not contribute anything to hydroponic planting and is best for other uses. There are wide spectrum LED lights that can be adjusted according to the need of the plants, these lights are expensive and is fit for a serious gardener.

When installing LED hydroponic lights follow manufacturer instructions and hang them directly above the plants. Since LED lights direct its rays downward no additional reflectors is necessary. LED grow lights produce virtually no heat, this means that they can be placed as close to the plants as possible for maximum effect. Some hydroponic lighting systems also have plant timers; this will control the lighting schedule to a pre-programmed time set by the gardener. If in doubt about installing LED lights contact an electrician for assistance.

Think you really picked the wrong thread for the question since hes touting LED's here.

"difference between t8 and t8 high output"
I'm taking it you meant to say t8 vs t5HO. Since I don't think there is much difference between the t8's.

T5HO is more efficient @ about around 10% from what Ive heard.
T5HO is more expensive at around 8-12$+ per bulb(HO) compared to T8's 3-6$ (pricing is based off 48" and rated @ 6500k, but it depends on the vender/manufacturer).

T8: 48" - 6500k - 2700 Lumens (32w) (CRI-78)
T5HO(high output): 48" - 6500k - 5000 lumens (54w) (CRI-85)
T5VHO(very high output): 48" - 6500k - 7200 Lumens (95w) (CRI-85)

T8: 84 lumens per watt - Price range: $3-6 (depending on the vender/manufacturer)
T5HO: 92 lumens per watt - Price range: $8-12 (depending on the vender/manufacturer)
T5VHO: 74 lumens per watt - Price range: $8-15 (depending on the vender/manufacturer)

You just have to factor in your wattage/price ratio.

Some people say it's best to replace the bulb before it goes out on it's own since overtime they lose their(less efficient?not sure the word) stamina. Just look @ the expectancy of the t8/t5HO/t5VHO bulb(s) and "maybe" base that into your purchasing decisions(those 20k-30k+ hours are probably based off some circumstances like temps/cooling(air flow)/etc and "might" not a suitable way to base a purchase off of, but I just threw that in there). Seems like a contradiction I just made, but you would have to do research on that.

"can I just get a cheaper fixture with my own reflector to grow the spinach"
Yep. Just make sure that they have a terms of purchase/return policy/some type of warranty, that seems suitable for you. This is the same for bulbs as well. The more fixtures/ballasts/bulbs you own, the more problems that could arise with them going out unexpectedly = more purchases/shipping(depending on where you buy them). I would make sure to have a small surplus just incase(bulbs). For ballasts, you just have to wing it and hope you purchase from a good batch or that later on down the road they don't go out. Maybe talk to it(ballast), take it out to a drive in movie, or sing it a song or two just to keep it happy :) .

If all you wanted to grow was spinach, hell any leafy green. I would just go with t8's. More places carry their fixtures/ballast/bulbs locally from what I know(home depot/lowes/etc). Their prices are not that expensive either. The cost per fixture of the t5's are up there(high), but you're getting more for your money. The real question is, how much do lumens/cri affect a grow and at what rate do they increase it at(if any). Also have to factor in lumens per sqFT. There are charts out there that base sqFT of growing off of watts(haven't seen any about lumens).

For example: (based off of watts :\ ) (if watts per lumens were average then it would I guess be more legit)
4' T5 (4 bulbs) - 216watts - 2.5' x 5'
4' T5 (8 bulbs) - 432watts - 4' x 6'

If you do some more research and come across any videos of people comparing multiple t8 grows versus t5 grows using the same conditions/solutions then I would love to see that(as long as their not peddling a product behind their "research"). I plan on using t8's and the grows that I have seen from t8's resulted in great results, but it's the same for t5's.

[mikegip]

Sorry we jacked your thread, but it didn't seem like it was going anywhere to begin with.

[mikegip / homehydro]

Carry on.

Forgot to mention reflectors. Depending on how many fixtures you plan to run. I would forget about purchasing a(another) professional reflector and use mylar that is attached to cardboard with 3m spray adhesive or double sided tape.

Since you said, "my own reflector". Assuming you've already bought one, just go with that. The mylar/cardboard thing gives you the ability to cover more ground though. Mylar is also pretty good @ reflecting light(90-98% light reflection). Space blankets(mylar) are cheap as well. Plus if you ever plan on going to space, you might have some left over.