I just came across this thread again and way too late but I may as well answer it. lol
Okay, just so I am clear on this. Remember, I'm not a techie, so please hold my hand. Is this a magnetic/electric ballast?
View attachment 56965
Magnetic/electric and not electronic. See the circular starters in the centre of the unit.
Here is something I read :
Life span of flourescent lights
Standard-- 6-18 months
T5---------- 6-8 months (At this approx time color dissipates)
T5 Ho------ 16-24 months (Hot and need fans)
CFL--------- 12-28 months (Hot and low dissipation)
If this is wrong please correct.
This comparison confuses me for T5HO has the highest lumens but least lumens/watt. What does this mean?
T8-----------------------------T5------------------------T5HO
av. lumens: 1845--------av. lumens : 1758---- av. lumens : 2803
lumens/watt: 73.8 % ---lumens/watt : 83.7---lumens/watt : 71.9
The problem is whoever tested that detailing 'tube life' when what they have tested is 'tube life in this setup'
T5 and T8 tubes WILL most definately last longer than T5HO. That is fact. however in those setups the standard tubes are being run on magnetic ballasts. That ballast is making the standard tubes run out quicker. The T5HO will most definately be on an electronic ballast and therefore it is the difference in ballasts that is giving them their results.
If all were run on electronic ballasts you would only need to change your standard tubes every 3 years before there was any relevant dropoff in output. The T5HO by its nature of burning hotter and brighter would drop off sooner. Probs circa 2 years.
Then they are giving lumens/watts/inch tests without quoting like for like. The results are correct but they are 2 different tests and need to be done like for like.
They say that the T5HO tube gives out more lumens per inch. Of course it does it is higher power than the standard ones even though it is the same length.
Then they say however it is less lumens per watt. that is true. If you get 2 x T8 tubes and add up the lumens then get 1 T5HO that is the same wattage as the 2 T8s added together then the T8s will be higher.
This is because of the nature of the beast. T5HO are overdriven. Their advantage is more light in smaller space. The trade off is that for the advantage you lose a little bit. however it means you can have a smaller unit with higher light. Particularly useful in reef.
That is not our goal though. We shouldn't be obsessed with packing huge light into small space in planted. We don't need huge light but we do need coverage and spread. The old style Juwel / Fluval hoods were quite good at this as they spaced the tubes out well. The modern style luminaires miss the point for planted and pack all the light in a pretty and nice aesthetically looking slimline unit. Looks good but then you need more light so that the further regions are getting enough.
That bulky outdated old unit was performing much more efficiently because it was better for coverage and spread and therefore needed less wattage!!! We must have pretty though rather than best performance!!!
I went to a lot of effort to make a diy light. It started out cheap and ended up costing as much as much as a dual T5HO light system cost
here This is cheap because it is made by Current USA. Their fans are loud but that is an easy fix.
You prove my last comment right
You are comparing your DIY unit with the retail unit and saying 'I could've bought the super dooper retail unit. Your unit will be better if you have spaced it out properly.
When doing a comparison you must always compare like for like. If your unit is spaced out well then you can't feel bad if it cost the same or even more than a retail unit where the tubes are packed in together.
If you compare your DIY unit to something better that is different then you have to be sure that it is better. In most cases for lighting a planted tank the retail units are nowhere near being better.
I prefer the T5 to T8 for my 29 gallon tank, 30in, because the the T5s come in 30 inches. The T8s are 24 inches.
Also I found with T5HO I would need to inject Co2 thus the tank would no longer be a low tank, which how I want to keep it.
Thats fine. T5NO outperforms T8NO. T5HO is the problem
AC