Are these 48-inch tubes? Which means four 48-inch tubes over the 75g? If yes, this is way too much; you will certainly have algae issues. I only have two of these over my 70g and I have to watch the duration or algae takes control. To balance this much light, you will need CO2 diffusion, plus daily nutrient dosing. Floating ploants would help, but not sufficiently to balance the high light.
You can't go by watts per gallon anymore, as the newer tubes are much more efficient that the older. Plus, intensity has to do with how the tube is made, the phosphors, and the wavelengths. As a simple example, the Life-Glo 6700K is twice the light intensity as the Aqua-Glo in the same sized T8. And the newer 32w tubes are brighter (more intensity) than the older 40w in the same length and type.
The photos below show my 70g, and the 5-foot 115g which has the identical same light (two T8 tubes in 6500K).
Byron.
Are these 48-inch tubes? Which means four 48-inch tubes over the 75g? If yes, this is way too much; you will certainly have algae issues. I only have two of these over my 70g and I have to watch the duration or algae takes control. To balance this much light, you will need CO2 diffusion, plus daily nutrient dosing. Floating ploants would help, but not sufficiently to balance the high light.
You can't go by watts per gallon anymore, as the newer tubes are much more efficient that the older. Plus, intensity has to do with how the tube is made, the phosphors, and the wavelengths. As a simple example, the Life-Glo 6700K is twice the light intensity as the Aqua-Glo in the same sized T8. And the newer 32w tubes are brighter (more intensity) than the older 40w in the same length and type.
The photos below show my 70g, and the 5-foot 115g which has the identical same light (two T8 tubes in 6500K).
Byron.
On the note of lighting, how then do I determine how much light I have and which plants would or wouldn't be good for the tank? With just the 2 bulbs (6500k) am I low or moderate lighting?
Moderate. Avoid the high-light "carpet" type plants, and stem plants generally do not work, except for Brazilian Pennywort.
Alright. I will have to go to my lfs when I get some time and see what they have. Oh, and Zorranet had mentioned that anubias is a bit of a pain, I just recently put some nana in my 10g at work. Bulbs (2) are 6500k zoo med and I dose with leaf zone, because I'm growing java ferns and it was what I had. Is there anything else that I need to do? When I planted it, I made sure that it was held down enough not to float away, but the rhyzome isn't under the gravel.
Anubias, JAva Fern and Java Moss are low light requiring, so they will be fine in moderate light. But best with some shade (those floating plants again, lol). Anubias and JF tend to attract brush algae if they are in direct overhead light.
Being slow-growing (low light plants are such), they also need less nutrients, which is why they will usually fare fine in almost any situation.
API LeafZone provides iron and potassium, which are two of 17 nutrients aquatic plants need. So if this seems to be working, fine, use it up. But for your other tanks I would recommend a more complete fertilizer, as you will haver more light and faster-growing plants. I use Seachem's Flourish Comprehensive Supplement, and another is Brightwell Aquatics' FlorinMulti. Both are intended to provide the correct balance of the necessary nutrients, but only as a supplement. Fish foods (the organics) and water changes supply the rest. This works fine in low-tech set-ups, but can get very expensive in high-tech where daily dosing may be necessary. Some recommend mixing your own from dry, but I prefer using the liquid preparations that are balanced, and for me have worked well, as those earlier photos indicate.
The way I said that sounded so defensive. Gotta clear my name, yo! haha
Slow growers are, as Byron said, fine in most situations. I suggested fast growers as a way to compete with algae for nutrients and keep it at bay. I think it's simply that people don't understand the purpose of having plants when they fill a tank with all slow growers (which happens all the time). They just can't compete with algae on their own, so they need some help from fast growers to soak up the extra nutrients which algae will take advantage of if given the opportunity.
Algae is kinda like a fat kid sitting at a table with bunch of senior citizens in wheelchairs when it's algae vs. slow growers. Put some doughnuts on the table and the old folks are gonna starve without some basketball players (fast growing plants) around to block the fat kid's view of the doughnuts long enough for everybody to get a fair share before he gets a hold of them. The basketball players and old folks may be pickier than the fat kid when it comes to doughnuts, but they all have to eat or somebody dies. Starve the fat kid!