Emily, I highly doubt you are going to find spectral aluminum at a hydroponic shop, but check it out.. maybe them shops are mose sofistacated out there :mrgreen: . I have not found one out here that even know what it is :mrgreen: whare you will find it is at a sheet metal supply place. there are several names for it everbright being one. the stuff you will find in hydroponic stors is mostlikely polished aluminum which doesent even come close to the reflectivity of spectral aluminum.

Steve

hmm

Haven't gone to look - I do know what a spider light looks like..... :neutral:

Steve ... take a look at the J&L website under lighting and tell me if the stuff that they are using for reflectors for MH are spectral aluminium ... the guys at the hydroponics store did say the stuff was polished aluminium with a 95% reflectivity which is the same reflectivity that the J&L reflector claims to have ... is polished aluminium with 95% reflectivity then the same as everbright or spectral aluminium ?

Cheers

everbright (spectral aluminum) is a higher grade and comes in at 98% reflectivity, if they are saying 95% then they are using some grade of spectral aluminum which surprised me as the answer I got out here is that you want a dispersaly type of reflector to avoid hot spots on your plants not at true reflectance type.

The problem with spectral aluminum is you have to know what metal was used to coat the aluminum. aluminum its self is very porus and no mater how you polish it you will never get close to the reflectivity of spectral aluminum.

When they make spectral aluminum they coart the aluminum with a smaller grained metal that allows for a smoother surface and hence more reflective. Silver is a very commen one that will give you about 93 to 95%. if you can find the products that are done using nickel, the reflectors I am running are tested at 98.9% reflectance and they are high grade nickel coated.

Steve

Steve the aluminum is not available at the hydroponics shop. The hydroponics shops has north american green house supply manufacture the reflectors they sell in the store. It is a rather large shop with several impressive looking machines, as well as a number of shears, breakers etc.

I talked to the guy that actually makes the stuff and they buy the aluminum in 10 foot sheets and refer to it as "spectral aluminum". It is coated with a blue plastic film to prevent scratching and it is certainly shiny. Because they go through quite a few sheets of the stuff they have some scraps around they use on smaller projects. They also have another dispersal type of reflector material that is shiny and bumpy.

One might argue that a material with a reflectivity that is 98.5% is better than one that is 95%. Once you place this materail in your hood and you expose it to a high mosture enviroment...well unless you are doing dailly cleanings there is not much difference. And even with dailing cleaning ... it only makes a difference for the first few hours.

nickel is non reactive whare silver is reactive a little. I could scan a metal reactance chart from work but i would have to find one :mrgreen: for this reason alone the nickel finnish would be mor durable in the enviorment we use it it. I cleaned my reflector [nickel one] after 6 months of abuse and it looked like it was brand new, my old one [silver one] and it looks aged, the nickel one had more salt on it. so from experiance I can tell you the fin ish does matter but it is up to you to decide how much. I think if Delphinus can rember whare he got the price from it was like 3.50/sq ft [1/2 the price i can get it from on the island :rolleyes: ] so it is a cheep reflector at that price.

Steve

:sleeping:

This must be what happens in the later years. Falling asleep right in the middle of an exciting thread!! :razz:

That's just "Lumper Talk" Brad.

ok I hate to have to ask but what is "lumper talk"?

Steve