New lighting - how much brighter?

I am upgrading my 30g tank from 2 - 24" T12's (ODNO 2X) to a Coralife T5 dual light strip (18W per bulb 30"). How much more light is this likely to give me, if any? The reason I am upgrading is because something weird happened with the old fixture and it melted part of the plastic when a bulb failed, so I don't trust it anymore. Also because it will cost me almost as much to replace the bulbs with the proper T8s as to get a new fixture.

 

I just found this spreadsheet I forgot I had that does a calculation of relative 'wpg' based on the type of bulbs and size of the tank. I can't find where I downloaded this originally on the web but someone did this up to provide a sort of more accurate comparison of wpg between different tanks and types of lighting. Obviously it's not exact. When I plug in the numbers I get about 1 wpg with my current setup, compared to 1.2 with my new setup. So maybe about 20% more lighting than I have now. Which would be just fine with me. Does that sound approximately correct?

Another issue that will be addressed is that my bulbs now are only 24" so the sides of the tank are very poorly lit, this will be addressed with a 30" light strip which will distribute lighting more evenly.

 

Yeah, I have a T5 HO on my sw tank and it's insanely bright for just having two tubes. I'm sure the NO are not like that. I found this comparison chart:

Lighting - Pets & Ponds

It compares the lux of various light fixtures. The Coralife NO T5 is fairly low especially compared with the Hagen HO T5 which is what I have on my other tank. The wattage is double but the lux is actually triple. I would have bought the Hagen single tube fixture if they had it in 30" size but they don't.

 

Not to defend them, I have no idea if the readings are correct or not, but this doesn't stand up to logic. The Hagen T5 HO is nearly $100 less than the Coralife 4x65 watt and the bulb replacement cost is nearly one third the cost of the other unit, yet they are saying it has nearly 2000 more lux. Seems counterproductive if their idea is making money off of people by skewing their numbers. It also seems reasonable that on average, you will pay more money for something that provides more light.

For the Current and Coralife fixture comparison, it could be reflectors, it could be ballasts, it could also be different types of bulbs too. As mentioned, lux measures what the human eye sees, and different bulbs produce radiation in different areas of the spectrum, some of which is not visible light but may still be useful. The Current fixture is about $50 more expensive than the Coralife, you would think there would probably be some reason for that.

I agree that getting information from people who are selling you equipment is not the most unbiased method and PAR would be better. If anyone has this information (comparisons of various lighting fixtures on the market) I would be very interested in seeing it. I take everything with a grain of salt, especially if it's coming from someone trying to sell me something. But without a better source of information or the resources to do my own testing, I'm stuck with it, such as it stands.

 

I didn't say I was convinced. Just that I have no other sources of evidence available so I have to make a judgment call on my own. Also, the future of the country or my own financial state is not at stake here. So the consequences of misinformation in this case are not that hard for me to deal with even if it is the case.