3x54W or 4x54W - 75G

[FSM]

I've been trying to decide how much light to get for my 75 for the past week. The tank will have pressurized CO2, so high tech. I am going to get a Catalina Aquarium solar T5 fixture, but I'm not sure if I should get a triple bulb fixture or quadruple bulb fixture.

Right now I'm leaning towards the 3x54W light. From what I've read, that will be more than adequate light, and with the 4-bulb fixture I would be much more likely to have issues with algae. Growth would be faster, which will be nice when I am first starting the aquascape, but once it is about how I like it having to trim every few days sounds like a PITA.

 

[Riiz]

I personally like 3x54watt over 75gallons, the plants might not pearl as early in the day, when I had 4+ bulbs going. But the lack of algae and weekly trimmings sure are nice.

Edit: Some 4x 54watt fixtures will actually allow you to run only 3 bulbs, but its best to ask the manufacturer first before assuming. But the Cataline 3x54watt fixtures are nice and you cant beat the price.

 

[FSM]

How often do you think I will need to trim with 3 bulbs?

I've sent an email asking CA if they can use the perforated solar T5 housing for the triple bulb fixture, because it looks cooler, presumably runs cooler, and the lights are spaced out seems like a useful feature because of the width of a 75.

 

[Riiz]

It depends on the weeds you're growing, in my experience the stem plants are what need a trim every week and the foreground plants need to thinned every couple weeks, so that they arent growing over each other.

 

[StarStruck8]

I have the Catalina Solar T5 4x54 on my 75 gallon with CO2...the plants are out of control! Then again, its my fault that I haven't gotten rid of all the water sprite yet. It takes over the tank in a matter of days! :swear: I need to trim most of the plants weekly. I enjoy the gardening aspect of it though.

I get some spot algae, but it isn't anything I can't wipe off during weekly water changes.

 

[FSM]

Do you use all 4 bulbs the whole time?

 

[StarStruck8]

The lights are on for 10 hours. I only use one set (2 bulbs) for an hour before the other set turns on, and then an hour before the lights go out.

 

[debaric]

The lights are on for 10 hours. I only use one set (2 bulbs) for an hour before the other set turns on, and then an hour before the lights go out.

This is good practice to use as it has proven to cut down on some of that opportunistic algae. I would go with the 4X54 fixture if you want certain deep red plants such as one of the Alternathera sp. You want to have the lights on full blast for at least 4 hours of the day and maybe turn one or two of them off for a few hours.

My Alternathera Roseafolia went 3 days without all 4 bulbs lit and it died. It was doing fantastic before that. Some plants just need super high light, not many of them, but a few do.

 

[plantbrain]

I'd use less.

I use 4x 45 W on a 120 Gal and it's plenty to grow the most demanding red and other stem plants.

4x 54 on a 75 is too much light really.
It's a waste.

You could run the front pair for 5 hours, then the have them turn off, and then the back pair come on for the last 5 hours.

That would work nice.

Less light= less CO2 demand= better CO2 stability= less algae issues= less fish stress= less nutrient demand= easier routine for you, less critical to stay on top of things.

Higher light is where the real mess begins for many aquarist and plants.

BTW, I've grown the best A reineckii at low light, 1.8w/gal without issues of any sort.

Another with less light due to the light being far away and the plants are shaded so it's a bit less even than the above T8 light example:

Regards,
Tom Barr

 

[FSM]

Thanks for the replies everyone. I bought the 3x54W fixture, it shipped today.