# Hacking the Fluval Vista LEDs (TC-420, Dual Strips)



## Kaiede (Sep 11, 2017)

So, I've been mucking with the TC-420 and the Fluval Vista. I've hooked it up to the TC-420, and I've setup two LED strips in both an 8.5g and the 23g. I've also measured the results using an MQ-210 PAR Meter. It's a bit surprising, but I'm sharing my results in case someone is interested. 

Hopefully it is interesting to a few folks who have asked about this in the past. 

Dropbox Link w/Full Instructions (Includes Clickable Links to Parts/Tools, no affiliate links)

*What’s the Benefit Here?*

Adding a second light into the hood is an easy, if not terribly cheap way to get more light into the Fluval Vista tanks without changing the look. In my case, I have to keep the fish in, and the cat out. However, it’s also true that the Vista lighting is very capable for low light work. So maybe you just want to keep the one strip, and control it with a TC-420. That’s not a bad way to get more fine tuned control of photoperiod and use the two channels in each LED strip to have more interesting effects such as mimicking sunrise or sunset. 

Some Measurements taken at the substrate of my tanks with an MQ-210 PAR Meter:

*Fluval Vista 8.5 Gallon (32 Liter) * (~9.5” of Water)

 One Strip @ 100% White + Blue: *~20 PAR*
 Two Strips @ 100% White + Blue: *~35 PAR*

*Fluval Vista 23 Gallon (87 Liter)* (~15” of Water)

 One Strip @ 100% White + Blue: *~30 PAR*
 Two Strips @ 100% White + Blue: *~50 PAR*

The numbers for the 23 surprised me the most as I wasn't expecting to be able to hit 30 PAR a strip of 5050s (Hagen gives conflicting values on the wattage here too, site says 8.4W, sticker says 10W). I suspect it's a mix of the lights effectively being an inch above the water with no glass over the tank, along with reflections happening due to the taller stature of the 23g. Since the tanks are a bit thin, being 10-12” deep, there’s not a lot of loss going from the front to back of the tank.


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## jeffkrol (Jun 5, 2013)

Just a bit more for people who what to live on the edge...
Switching from a 12V ps to a voltage adj. ps you can tweak out a bit more PAR at the the RISK of frying out the diodes..
I know probably shouldn't mention it but most strip designs are based on automotive principals where you may need to contend w/ voltages as high as 14V cont...

Soo.. w/a good stable power supply (Meanwell makes a few) you could possibly tweak more PAR out w/ a voltage boost..

NOW NO guarantee that Fluval didn't optimize their output (depends on the current limiting resistor) OR that the thermal properties can take it..
BUT.. It is possible and done w/ ribbons ect..
Probably wouldn't exceed 13V or so..but if one is buying a new power supply it is an option.. 
ALSO prob not necessary on the smaller models..
YMMV..

Just an FYI..

I do have some concerns w/ Fluval as to their "soft start" LED statement..
Though that is more of a "feature" than anything.
https://www.maximintegrated.com/en/app-notes/index.mvp/id/4481

opp's forgot.. Really nice writeup..


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## Kaiede (Sep 11, 2017)

jeffkrol said:


> I do have some concerns w/ Fluval as to their "soft start" LED statement..
> Though that is more of a "feature" than anything.
> https://www.maximintegrated.com/en/app-notes/index.mvp/id/4481


Yeah, it's possible, but the soft start is relatively long (30+ seconds). My multimeter immediately saw a 12V differential, which unless my electronics is rustier than I think, suggests PWM. So I kinda suspect this approach wasn't used.

Either way, that's all controlled by the LED Driver / Touch Switch box. Doing this cuts that out of the loop and lets the TC-420 drive the strips directly.

EDIT: Honestly, Fluval's design here is pretty modular and easy to replace broken parts so long as Hagen keeps making them available to purchase. I'm kinda impressed with a kit tank like this. Still a bit disappointed they don't just offer up the dual-strip that they include with the German version. A kit tank that comes with decent pack-ins, _and_ can hit ~50 PAR at the substrate (depending on thickness) for your medium light plants? Yes, please. But I guess they don't expect as many people to be doing planted tanks with the kits in the US.


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## jeffkrol (Jun 5, 2013)

Hmm.. most meters will "average" a PWM signal so output would look like 6V @ 50% duty cycle. At least that is how PWM control signls meter.
So the soft start might just ramp current....

Well all beyond my pay grade though..
Unnecessary w/ the TC-420 really..

You do have resistors on the strips right?
Like 1 resistor to 3 diodes..

The assumption is always tht the strips are driven constant voltage..which generally requires a resistor for current control.

Got freaked for a minute there when I saw 1 resistor per diode.. Forgot 5050's are really 3 diodes in one..
IF they use constant current proper drivers and you bypassed them you may be running on borrowed time..

OK took some time to actually look at the light parts list.. correct me if I am wrong.
Wall wart....touch switch..light..
Yea probably a PWM "autotime" inside that touch switch.
No "proper" CC driver ,

Can you get the numbers off the resistors? Just curious..


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## Kaiede (Sep 11, 2017)

The resistor codes are all 121 for all the LEDs, which is 120 Ohms, IIRC? The part list is correct, yes. 

Honestly, my multimeter is a RadioShack special. I couldn’t tell you what it would do with a PWM signal exactly, but it is possible you are right and I was just lucky here.

I think I did catch some flicker as well with the touch switch using 120fps video capture, but that was weeks ago. I’d have to run the experiment again to check to see if my memory isn’t faulty.


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