Does PAINTING the back glass affect anything?

[BigAl07]

I know many of us (self included) LOVE to paint the back of our tanks. This way we can "enhance" the decor of the INSIDE of our tanks without seeing what's going on behind the tank (wall, cords, JUNK). It's common practice to tape the tank and apply several coats of Black, Blue, White or just about any color of paint. Well read on... you MAY want to scrape the paint...



At MACNA-XX some of us had the pleasure of listening to
James Fatherree talk about aquarium lighting in general and specifically about Reef Lighting. He made mention of "You may go home and scrape that back glass after this speech today." Well he was right. If I could get to mine I would have scraped it the NIGHT we returned home. Next one will be different.

I'll just hit the HIGH spots and post links to his online articles (All of which are GREAT reading)

(All graphs are Top Down, front of tank depicted at Bottom of Chart)

Below is a graph of light readings of a tank with painted rear and clear front

Notice how the front of the glass is SO much brighter than the back all due to the painted (exterior mind you) surface.



*** Next Slide***
This one has the Painted rear and just for reference they taped a Sheet Background onto the front (tape meaning not adhered to glass fully)

Once again notice how much BRIGHTER the front glass is even with the "Sheet" background on it...


*** Next Slide ***
This one has Painted Rear and a "Wetted" front sheet (this keeps the Sheet in FULL contact with the glass)

Notice it looks almost IDENTICAL to the PAINTED side?

and for those who wonder which causes more loss Black or Blue backgrounds
Wetted Blue on Front is FIRST pic (same as above actually)
Wetted Black on Front is second pic

Almost NO difference in light from blue to black.:scram:

So maybe.. JUST maybe on your next tank consider an alternative to actually PAINTING the glass if you're wanting to "Utilize" as much light INSIDE the tank as possible.

For more details *lots of INFORMATION in his article* visit

Liquid Medium Publications


*** Disclaimer***
The above images and links are provided with WRITTEN permission directly from
James Fatherree and should NOT be re-used/copied without his written permission. All content copyrighted by James W. Fatherree

 

[lcstorc]

Thanks for hooking us up with the article. The talk was awesome and now I have the charts to remind me of the specifics. It will be interresting what I find with the Solaris and my Penninsula tank.

 

[BigAl07]

Yeah that's gonna be Fun to experiment with. Are you gonna "Chart" everything out so I can understand it all?

 

[Frankie]

Wow Allen, I was not going to paint the ack of my future upgrade for similar reasons. Great article dude.
Scraping the back of my current tank though is not something I considered. With the closed loop back there I have enough room to do it though. I will need to think on this.

 

[BigJay]

wonder what would happen if you used a more reflective color like white. I assume the problem is the blue/black is absorbing and the clear glass is reflecting the light? Or is it a prism effect from the glass? Very interesting.

 

[BigAl07]

No it has something to do with the GLASS itself. ANYTHING that's adhered to the glass changes the reflective properties of the GLASS. The light is being reflected BY the glass surface itself before it even gets TO the paint/sheet. On the link there is a simple diagram depicting what they think is happening. Anything touching the glass inhibits that "mirror" quality.

 

[sambrinar]

Well after reading this, I decided to remove the black background TG I didn't paint and it does make a huge difference. The only reason I had it on was to cover the cords etc, but I have removed alot of the stuff that was corded, just PH, heater and draw for the filter, all on one side.... and ....

I like it much better now.. Thanks Al

 

[BigAl07]

Ok here is the image I was talking about.. this is what happens when NOTHING is on the back glass at all

anything (regardless of color, texture, print etc) that comes into direct contact with the glass surface stops this "mirror" action and kills your light. Granted I would THINK that if it's a reflective background it might reflect back but that may or may NOT be the case. It may have some type of REVERSE light blocking because WATER it tight to the INSIDE of the glass possibly stopping that. This is all speculation on my part

 

[BigAl07]

I like it much better now.. Thanks Al

Wish I could take credit but I'm just the "messenger" here. I'm GREAT at copying other people's work

 

[lcstorc]

Guess we all need to start scraping the back of the tank now. Not just the paint but the corraline.

 

[BigJay]

I'd like to see more tests done with different qualities of glass and thicknesses. As it stands its pretty vague but does get you thinking. Take something like pyrex where the optical quality is superb or starphire and compare it to normal soda lime glass(reg. tank glass(ie green glass). The refraction properties are going to change substantially.
Thier are so many things that need to be analyzed beyond that like glass shape , angle of refraction. Geez I am going to be thinking about this all night.
I am going to talk to a few of the people I know that manufacture raw glass and see what they have to say.

 

[faust]

i wonder how this. painted back of the tank would pertain to thermal issues. since black absorbs heat and white reflect it

 

[lcstorc]

That's pretty much what James was saying at the talk. They tested a whole bunch of things but each test brought up more questions and more tests. At some point they had to stop and print up what they found at that point. They were also limited to the tanks and lights they were given. Testing like this could go on forever.

 

[BigJay]

That's pretty much what James was saying at the talk. They tested a whole bunch of things but each test brought up more questions and more tests. At some point they had to stop and print up what they found at that point. They were also limited to the tanks and lights they were given. Testing like this could go on forever.

cool. Thanks Lynn. And thanks Al for bringing this up. Since I am kind of a glass geek anyway this is very very interesting to me. I've wondered about dark spots I can see visibly in the tank and wonder why. I really wish I could have been there for that talk.

 

[BigAl07]

i wonder how this. painted back of the tank would pertain to thermal issues. since black absorbs heat and white reflect it

Not sure how much difference that would make since it's two different types of heat we're dealing with. Who knows really

 

[Snelly40]

what if we adhere a mirror to the back???
still wont see the cords or anything and would give a cool effect???

 

[wonderloss]

I think a lot of fish would spend a lot of time angry if they saw their reflections all the time. Species that are not too territorial might be alright, though.

 

[BigAl07]

what if we adhere a mirror to the back???
still wont see the cords or anything and would give a cool effect???

You're starting to dabble in physics... that's 2 doors down

What you have to realize is that ANYTHING adhered TO the glass will change the transparency OF the glass. I don't know what all is involved because we're working with several mediums here.... Factor in The GLASS itself (both inner and inner-outer surface), water, air and LIGHT! :tongue: If it TOUCHES the glass it changes the reflective properties..... now I'm and totally

 

[Octoman]

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Very interesting, looks like I'll have to scrape the paint off the back... I think it was Framerguy that used some sort of painted waterproof board (gator board?) that he attached to the back of his tank instead of painting (velcro would probably work well). That would still allow an airspace between the background and glass. I think I'm going to give that a try.

 

[BigAl07]

Good idea Mark Remember to take pics!

Hey do you have a PAR meter? Now THAT would be SWEET To do some "Real-World" testing....