I'm almost finished ( ehh, except for the aquascaping ...) with the technical stuff in ny new tank ( open, DIY amano style).
Some people might be interested in the lights I used and why
An open tank requires a pendant. So far so good.
I investigated 3 styles of pendants and tried them at home (many tanks to my LFS
) and I choose for a flat T5 pendant.
Why did I choose for this pendant :
1) MH or HQI
- not dimmable
- every year new expensive bulbs
- shining in your eyes when sitting on the couch
2) round T5 pendant
- spread was not enough
- ineffective reflectors
- last T5 lamp was shining in the eyes when sitting on the couch
3) the flat T5 pendant
- good spread
- no shining in the eyes
- very good reflectors
The shining-in-the-eye thing was a major point. I had for a while the round pendant working and it was truly annoying to look right in the bright T5 when sitting on a chair/couch.
The spread is also important to get enough light in front / back on the bottom.
Although Amana uses MH, I think he would haven choosen bright T5 pendants if they were available in his early years
They last longer en give more light than a normal MH.
The flat T5 has dimmable ballast and is controled by a light-computer.
They work with an electronic ballast ( EVG called here) wich have an extra option : dimmable via a wire 0 -10 V.
10 Volt means 100% light and 0 Volt means 0 % light ofcourse.
The middle two lamps are seperated from the 2 x2 outside lamps.
The computer controls the output via so called " curves". You can choose for instance :
10.00 - 11.00 > 0% to 50% ( gaining light in say 20 minutes and stay there for the rest of remaining hour)
11.00 - 15.00 > 50 to 100%
15.00 - 19.00 > 100% tot 40%
19.00 - 23.00 > 40% to 5%
23.00 - 23.30 > 5% to 0% (lights out)
( and choose another program for the other T5).
In my case : the T5's are paired. So 2 + 2 ( front and back) are connected and will dimm together. The 2 in the middle are dimmable seperately from the other 2 pair.
The cooling fans are cooling the "cold spot" at the T5 "ignition" point. You will gain about 20% more light compared to a normal T5-pendant.
Some pictures :
And here is the new pendant : 6 x 54 Watt , flat !!
Cooling fans ( noiseless ) on top for cooling the cold spot :
Every T5 has his own very effective reflector :
The computer controling the output ( 0 - 100% etc and timer) of the T5's :
Very bright light when 6 T5's are all on at 100% : hurting your eyes...
Situation at midday : 4 lights on at 50% (example here) :
And in the evening : nice lovely light :
Results today : massive pearling at 100%, very good growth.