[Zoidburg]

My OH has a 4' Oddyssea Dual Output T5HO light fixture. It came with the following bulbs.

1x 54W T5 10000K lamp
1x 54W T5 Actinic lamp

The actinic bulb has burnt out, and I figure that it's probably time to replace both bulbs. The tank has 1 bristlenose pleco, 3 black kuhli loaches and about 40-50 cherry shrimp? There's maybe 7 plants, mostly anubias, with some floating plants that came with the shrimp, so low light plants. No CO2 system, but the tank has a Fluval 405 and Fluval 406 filters, a Profile 4000 Aquarium Air Pump and Eheim 300w heater.


Considering the setup, I'm wondering if we should replace the bulbs with the exact same ones that came with the lamp fixture, if they should be replaced with 2x 54W T5 6500K lamps instead, or if there are alternative/cheaper bulbs from Hydrofarm, Amazon, Home Depot or (?) that would be better for the aquarium?


I've looked at some of the threads that mention PAR, PUR and other details about lighting and it's a bit over my head right now! I understand that the plants and fish would do fine with lighting in 5000k to 10000k (since we're speaking fluorescent) ratings so if I were to outright buy replacement bulbs, I'd go for 6500k with a CRI rating of 91 or above.

What's confusing me however is the red and blue spectrum's and how people have grown plants alright with lights that have 2700k rating. Essentially, go with natural daylight 6500k or replicate/replace what he already had? And best bang for buck bulbs source?



Thanks! :smile2:

 

[Bobbybills]

You can not go wrong with 6500K lamps but what you say is true. Plants will survive and grow in many tanks with many varying parameters. What strikes me as illogical is when people suggest that this light or that filter or these fertilizers maximize the effect one desires, yet these benefits cannot be compared to within the same exact environment. Therefore, how does one even know what is truly maximum or even best.

For instance, some prefer bright white light bordering blue for the wow effect while others say that the plants need more red. Both are happy with the results but given so many other system variables, the lights could be switched on those two tanks and both could become sub-par. Same for fertilizer. Some do, some don't, some do a lot, some do a little, and all are happy and cannot understand why the others don't follow their method, even though doing so would change everything within any given tank.

The light you describe is very blue so one would naturally say that all fish will look great, except certain colors could look "more or less" great.

 

[Convict with convicts]

I also use odyssea t5 fixtures. Best bang for your buck imop. Your oh had what's used typically for coral growth, hence the actinic bulb. Toss it, not doing you any good, besides looking cool at night you'll be at a much more plant compatible light level if you replace that bulb with another 6500 k. Do keep in mind that t5s typically lose par at around the 6 month range. This is debated though I play it safe and replace biyearly. You can find a pack of 8 or 12 or your bulbs on amazon or eBay relatively cheap. I myself have come to appreciate the looks of t56500 bulbs on my tank. As far as getting plant growth in different Kelvin ratings, yes, it is possible. But for fast vegetative growth you'll want it the 6,500 k range. Other Kelvin ratings would prompt plants into other possible stages such as flowering, reproduction, etc. Generally in aquariums were more interested in fast overall growth and light that's somewhat pleasing to our eyes. So we just rock with the 6500k. But tons of people here and elsewhere have used different Kelvin ratings with success... My best to you and yours?

 

[Zoidburg]

Much appreciated CWC! That makes sense! Found a set of four on Amazon that may purchase to replace the bulbs with... considering the age of the fixture, and believing that it still has the original bulbs, I think it's high time to replace them!



Decided to take the KISS method with a 10 gallon, wasn't sure if I should do the same with the 90 gallon tank or not, and have decided to as well for that one, thanks to your reply.