Growlights: Building the Perfect Grow-Box

Presumably how these T5 lamps have become so skinny, relative to the Tubes when "I were a boy", and yet still output the same light. Probably just that manufacturing can now make the tubes, and all the connectors etc., to the much smaller tolerances?

 

Yep - if in doubt, I suspect the answer is always - its cheaper.

 

If you still have this Jenny I would be interested. Amy x

 

I bought this Diamond Mylar for my little light box . About £5 a square meter on Ebay. Seems tough and durable so I can roll it up , when I pack everything away at the end of the seedling season.
A concern , I use a little plug in timer to turn the LB on and off . I am never 100% happy of the little timers with the press in sections , safety wise . Is the switching mode more reliable on a digital one ?

 

I use the mechanical ones too. I have a 15 minute resolution timer, and I have used that where I want intermittent operation - e.g. a fan in my conservatory to keep the air moving in Winter, 24/7 unnecessary I think, 50% of the time is fine, and I reckon that 15 minutes on and 15 minutes off is just fine. Not sure you could program that many on/off cycles with a digital one?

However, there may be an issue that switching of Florescent lights with a cheap timer may be a problem, over time, and you might need a contactor to do the actual switching part.

 

I use the mechanical segmented timer , but I am concerned at a £3 bit off kit switching on and off in the house. Why would switching fluorescent lights make a difference ? My set up only uses two 30w daylight CFL's , so maybe I am getting a tad paranoid !

 

My understanding is that switching a fluorescent lamp has a high start-up current, which can cause wear & tear on the contacts of a "cheap" switch, and can cause them to arc / fuse.

Whether this is actually the case, and in particular whether it is the case with a 30W lamp, I'm not at all sure I'm afraid :(

I am pretty sure that switching something like a 400W Metal Halide does need to avoid using a cheap timer (i.e. use a Contactor instead) ... but no idea at what Wattage, type of device, the dividing line needs to be drawn.

Anyone also active on a DIY or Electrical forum who could ask?

 

I had a chat with the electrical maintenance manager at work , he said that he prefers the segment timers and they should be OK as long as you are switching under 1kw. So I'll go with that