I am far from being an expert at it but my take is that there may be a few things you try when working on lowering the amount of brown algae in a freshwater tank.
Using lamp timers to limit your lighting hours downward, keeping in mind that the more highly-evolved plants need about a 4 hour block to get themselves going (so any given stretch of light time should be a minimum of 4 hours is my understanding) whereas algae, lacking the biochemical machinery that needs all this time, will get a boost from short periods of light in addition, allowing them to "get ahead" of you in your battle.
So, what I'm saying about light is that first, its a major thing, absolutely essential to both plants and algae and yet you want to limit its time to combat the algae but you are hampered in doing this because you can only go "downwards" while preserving these 4-hour blocks.
So, another approach that has been mentioned here on TFF is to find floating plants that will work in your tank and then use these, possibly in conjunction with brighter lighting. As I see it, this would be adding a couple of factors. Since there is presumed to be less trace ammonia up at the surface where we all try to keep up better water movement, the brown algae (which, in my experience really like to find trace ammonia in tank corners and other areas of less flow) the higher light up there will push some higher growth in the floating plants, causing them to compete at a slightly higher rate for the given nutrients in the water column, leaving less for algae. Meanwhile, the low-light plants and the brown algae below will be receiving less light intensity, which should be good for both of those things.
OK, so light is perhaps the major factor to work with. Then moving on, another important factor is maintenance. Each time you gently clean the brown algae off of the places it is established and then remove some of it in the followup water change, you are getting ahead in a major way because millions of brown algae cells are being taken out of the tank. So thoroughness and frequency of these types of maintenance sessions is a big factor that can be in your favor if you have the will to do the work.
Yet another important factor is circulation and water flow in your tank. Brown algae likes those little still places where the flow is blocked or still. It might be in the corners between glass and substrate, where it can still get light but where flow as stopped and microscopic amounts of trace ammonia are available to it (not the sort we can measure of course.) It might get an advantage close to leaves, just because the texture of the leaf provides less actual flow and some attraction for ammonia to hang out. So, the idea here is that overall water flow, provided by our filter pumpheads and any additional power heads we use can help to battle the brown algae. Of course, its a balance, as we are also trying to provide a nice home for our fish.
OK, so we've got light, maintenance and flow as important considerations, what else? Well, there is also supplemental plant nutrition to consider. Our non-algae plants need, ideally, a balanced diet of the 17 or so basic nutrients that sustain them. Real life never really presents that at any given moment of course, but to the extent that we can learn to try and help that to not be -way- off, we are helping them to have what they need to grow, yet not leaving leftovers for the algae "opportunists!" Most, if not all of these nutrients can come from the fresh tap water that comes in or the organic waste that fish help out with. But we can also learn to "read" our plants and begin to pick up on little signs that they give that we can use to adjust the small amounts of supplemental nutrients we might dose to the tank or the amount of that that we do. Learning that takes time, but is certainly a worthwhile skill to be building on as a beginning tank keeper.
Using otos or other fish to add to the control is yet another factor, but of course is not one that necesarily makes things easier, instead, it is just another additional variable on top of the other basics that adds its own things to be watched and understood. Its right for some tanks and keepers and not for others. Anyway, those are just some thoughts on brown algae.
~~waterdrop~~
