Sorry I am still a little confused....would the CFLs work better for smaller numbers of plants on shelving because of the light pools, and the long tubes work better when you have more plants packed on the shelves because of the more even light coverage? I too have to add new lights for my shelving units. Currently I have a mix of a few very old shop lights and, T5's. I was going to add some CFLs for one area for on top of one of the shelves. Various other posts had convinced me that the T8's were cheaper than the T5's, and that I should try some of those instead of the T5's. Could someone tell me where you get cheap T8 fixtures - around here they are $75 for 4' 2bulb fixture....which makes them more expensive than the T5 fixtures...so I am sure there must be somewhere that I have not thought of. I am bedridden - so I have to do all my research online, and then beg a favour from a friend to do the actual shopping - so any help is appreciated. Also any ideas on where to get the CFL bulbs mentioned. I am in Canada but the big stores are here also. Thank you for your help.

A few years ago I needed to increase the light in a kitchen lit by an overhead fluorescent fixture. As I found it, it had two 4-foot T8 735 tubes and an "energy-saving" (read: light-reducing) instant-start ballast. To make it brighter without the hassle and expense of replacing the lamp fixture, I replaced the ballast with the highest-overdriving ballast I could find that could drive a pair of F32 T8's. After some online research, I wound up buying a Philips Advance IOP3P32HL90CSC (a.k.a. IOP3P32HL90CSC3SI , sometimes with several hyphens inserted for readability). It can drive either 2 or 3 bulbs, but overdrives more when used with 2 bulbs. This was a few years ago, there might be something better now, but 1.37 ballast factor replacing a 0.87 or something makes a substantial improvement in brightness. I also upped the brightness slightly by replacing the TL735 bulbs with TL830 or TL835's which are slightly brighter and have better color rendering, which the eye perceives as adding brightness. Re: Philips TL930/TL950 :I've used both the Philips TL930 (95CRI) and TL950 (98CRI) 4-foot tubes., which fortunately I was able to buy two at a time from the local retailer. The TL950s illuminated my kitchen; the 930s went into a basement rec room where they match the color temperature of halogen downlights. The TL950s won't blow you away upon first turning them on - they look like typical cool/sunlight fluorescents at first. Its just that the different colors really pop out well and cleanly and the colors jump out at you rather than being dulled. The kitchen there has no windows, and in the morning sunlight, I noticed the ambient light from the windows across the apartment matched the TL950 light in the kitchen perfectly. If I take pictures with a film camera loaded with standard color film (daylight-balanced), pictures taken with available light indoors under typical "cool white" fluorescents lend an awful greenish cast to everything, but those shot under TL950s had perfect color. That says boatloads about the TL950's color accuracy. As for the lower lumen output, I again compensated by overdriving them by about 25%. I needed a rapid-start ballast for these fixtures, and went with a GE/Motorola ballast that overdrives a pair of F32 T8's with a ballast factor of about 1.20 IIRC, not as bright as the Philips I mentioned above but adequate for my needs here, plus I needed rapid-start rather than instant-start for this application. There are (were?) 2700K, 3500K, 4100K, and 6500K versions of these bulbs sold in Europe. Too bad they aren't sold in North America.

The sprawlmarts where I live (and they are HUGE Walmarts with full grocery) do NOT carry shop lights. Not all sprawlmarts are created equal! ;-) I have one T8 and one T12 fixture. In some ways I like the T12 better for the plants because it seems to be wider. The bulbs are a little bigger, and they are spaced a little further apart, so the overall shop light is wider. When I slide my tray under it, I seem to get much better coverage then I do from the T8. Here in Southern Ontario, I can't find a shop light for under $35.00. I bought a T8 for $39.00 as it seemed to make sense that if I was going to fork out that much money, what is another $4.00 for a more energy efficiant fixture that will likely still have bulbs available and easy to find 5-10 years from now?? (sorry about the hijacking the thread, from what I have read, either fixture is fine, they both put off the same amount of light. I am sure you can find fixtures that are wider and thiner in both t12 and t8. This has just been my personal experiance!)

OK, I'm just going to throw these out there. Forgive me. I haven't sorted them yet and I have a terrible awful hateful cold. At my age a cold is just not the same experience it used to be, LOL! So here are ALL my links, in no particular order, and probably some repeats, in a giant noodly mess. http://www.tomorrowsgarden.net/node/22 http://reocities.com/heartland/pines/7557/overdrv1.html http://www.buylighting.com/T8-Fluorescent-Ballasts-s/616.htm http://www.fatalii.net/Articles/Customized_fluorescent_lamp_system http://www.acuitybrandslighting.com/library/ll/documents/specsheets/td-100.pdf http://www.standardpro.com/ballasts-info/fluorescent-ballasts/faq#crest-factor http://www.irf.com/technical-info/designtp/temp004.pdf http://www.lightingassociates.org/i/u/2127806/f/tech_sheets/Basics_of_Ballasts.pdf http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/t8/03-t8-power.asp http://forum.grasscity.com/absolute-beginners/564033-lighting-guide.html http://forums.gardenweb.com/forums/load/lights/msg1023085115379.html?21 http://web.archive.org/web/20040629124310/http://forums.gardenweb.com/forums/load/lights/msg111229472000.html http://www.geocities.ws/overdrive_lights/ http://forums.gardenweb.com/forums/load/lights/msg0200530730707.html http://forums.gardenweb.com/forums/load/lights/msg0213125528645.html http://web.archive.org/web/20060102052948/http://www.plantedtank.net/odno.html http://www.plantedtank.net/forums/showthread.php?t=21257 http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/t8/03-t8-power.asp http://web.archive.org/web/20080103183037/http://www.geocities.com/teeley2/overdrv1.html http://web.archive.org/web/20080223040411/http://www.plantedtank.net/forums/lighting/21257-odno-measurements-power-consumption-vs-light.html http://www.plantedtank.net/articles/DIY-Light-Hood-Fan/10/ http://web.archive.org/web/20080220090814/http://www.lightsearch.com/resources/lightguides/ballasts.html http://web.archive.org/web/20080223040411/http://www.plantedtank.net/forums/lighting/21052-comparison-lighting-types-lumens-watts.html http://assets.sylvania.com/assets/documents/faq0042-0700.4cdec34c-d464-4f9e-a6cf-0b6ec9a934c0.pdf http://www.donsbulbs.com/cgi-bin/r/d.pl/initial_lumens.html http://reocities.com/Heartland/Pines/7557/overdrv1.html https://www.icmag.com/ic/showthread.php?t=17260 http://www.oocities.org/teeley2/overdrv1.html http://www.acuitybrandslighting.com/library/ll/documents/specsheets/td-100.pdf http://www.standardpro.com/ballasts-info/fluorescent-ballasts/faq#crest-factor http://www.irf.com/technical-info/designtp/temp004.pdf http://www.lightingassociates.org/i/u/2127806/f/tech_sheets/Basics_of_Ballasts.pdf http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/t8/03-t8-power.asp Parts and supplies: https://p11.secure.hostingprod.com/@nextechlighting.com/ssl/product_info.php?cPath=1&products_id=93&osCsid=759ef60819b0f4e334968e847d419dc0 http://www.lowes.com/pd_420867-43921-MXL-103_4294565967__?productId=4013485&Ns=p_product_price:0&pl=1¤tURL=%3FNs%3Dp_product_price%7C0%26page%3D1&facetInfo= http://www.lowes.com/ProductDisplay?partNumber=163719-337-SNF232RC&langId=-1&storeId=10151&productId=3335372&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1 http://www.amazon.com/Sunpark-SL15T-electronic-multiple-fluorescent/dp/B005HQL0KQ http://www.amazon.com/gp/product/B00ER7NYDM/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=1944579862&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B005HQL0KQ&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1512MJV7X1SG1RSWWFBD http://www.amazon.com/gp/product/B005HR0FPG/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944579862&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B005HQL0KQ&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1512MJV7X1SG1RSWWFBD http://www.panbo.com/archives/2013/12/3m_scotchloks_is_my_love_so_wrong.html http://www.goodmart.com/products/halco-lighting-e232is-120-r-sl-50118.htm http://www.homedepot.com/p/Lithonia-Lighting-2-Light-White-T8-Fluorescent-Residential-Shop-Light-1233-RE/202994372 http://www.lowes.com/pd_245546-58659-NXU-6001-B_4294857041__?productId=3168049&Ns=p_product_price:0&pl=1¤tURL=%3FNs%3Dp_product_price%7C0%26page%3D2&facetInfo= http://www.lowes.com/pd_420867-43921-MXL-103_4294857041__?productId=4013485&Ns=p_product_price:0&pl=1¤tURL=%3FNs%3Dp_product_price%7C0%26page%3D2&facetInfo= http://www.homedepot.com/p/Commercial-Electric-Rugged-2-Lamp-Hanging-Fluorescent-Gray-ShopLight-CESL402-27/203725928 http://www.homedepot.com/p/Lithonia-Lighting-All-Season-Shop-Light-4-ft-2-Light-Grey-T8-Strip-Fluorescent-1242ZG-RE/202052422 http://www.lowes.com/pd_163719-337-SNF232RC_1z0vgb3+1z0vjm2__?productId=3335372&Ns=p_product_price:0&pl=1¤tURL=%3FNs%3Dp_product_price%7C0%26page%3D1&facetInfo=In Store http://www.homedepot.com/p/Lithonia-Lighting-2-Light-White-Electronic-Channel-Fluorescent-Strip-Light-C-2-32-120-GESB/100543144 http://www.homedepot.com/p/Commercial-Electric-Super-Bright-3-Lamp-Hanging-Fluorescent-Silver-Black-ShopLight-CESL404-05/203725921 http://www.homedepot.com/p/Lithonia-Lighting-2-Light-High-Output-Multi-Volt-T5-Compact-White-Fluorescent-Strip-Light-ZR-2-54T5HO-MVOLT-GEB10PS/203137160 http://www.homedepot.com/p/Lithonia-Lighting-4-Light-Grey-Heavy-Duty-Fluorescent-Shoplight-1284GRD-RE/202968125 http://www.homedepot.com/p/Philips-4-ft-T8-32-Watt-Daylight-Deluxe-6500K-ALTO-Linear-Fluorescent-Light-Bulb-10-Pack-422949/203466585?N=5yc1vZbm3zZ1z0twpmZ1z0vvri http://www.homedepot.com/p/ViaVolt-54-Watt-4-ft-T5-Fluorescent-Replacement-Lamp-10-Pack-VT54B-10/203891792#customer_reviews http://www.homedepot.com/p/ViaVolt-4-ft-T5-865-High-Output-6500K-Fluorescent-Grow-Light-Replacement-Bulb-VT54B/203124383 http://www.homedepot.com/p/Philips-4-ft-T8-32-Watt-Daylight-Deluxe-6500K-ALTO-II-Linear-Fluorescent-Light-Bulb-2-Pack-422963/203466587?N=5yc1vZbm3zZ2bcoyeZ1z0twpmZ1z0vvri http://www.homedepot.com/p/Halex-3-8-in-Twin-Screw-Non-Metallic-Cable-Clamp-Connectors-5-Pack-20511/100133208 http://www.amazon.com/dp/B0051QKTRC/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=15S72TD6TYB1N&coliid=I2UG7LD6N0IEB8 http://www.amazon.com/dp/B002CYVGX2/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=15S72TD6TYB1N&coliid=I1BMFTJI3E3ISE http://www.amazon.com/dp/B005CJBIPA/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=15S72TD6TYB1N&coliid=I214UIEMT2RDC0&psc=1 Here is a link that might be useful: Pulley system to raise and lower fluorescent strip lights This post was edited by zensojourner on Thu, Nov 20, 14 at 2:02