Brown Algae Problem - Help

[nzafi]

I have started developing a bad case of brown algae on my 180g tank. I have started cleaning it but I would much rather prevent it. I have done some reading and came up with the following causes:
- High nitrates
- High silica
- Too much light
- Too little light

I do not think I have high nitrates. It has been a while since I tested by the only inhabit in my tank is a 14in aimara wolf fish that eats 5-7 times a week. I run an auto drip on the tank so it essentially gets a 20% daily water change. When I last tested it was hovering around 10ppm but will check again.

The tank is somewhat close to a sliding glass door. During the day for a couple hours it can get direct sunlight on part of it if it is sunny. I thought this was the initial cause so I stopped running my light. However, I went from having minimal algae where the sun hits to a lot more algae over time to places the sun does not touch. This is making me think I have too little light. No idea this could be a cause.

The other factor is that my area has extremely hard water. I do not run RO water as I have a 24/7 drip that goes through a sediment and carbon filter to remove cholorine and chloramine. Could hard water be leading to algae problems? Is hard water naturally high in silica?

Thoughts?

 

[Leebtattoos]

Direct sunlight can definitely cause all sorts of algae. My tanks usually get brown algae when my nitrates are high. I mean 20% wc a day should keep them down, but if you don’t test, you’re just guessing.

 

[nzafi]

Direct sunlight can definitely cause all sorts of algae. My tanks usually get brown algae when my nitrates are high. I mean 20% wc a day should keep them down, but if you don’t test, you’re just guessing.

Checked it tonight and it’s at 25ppm for nitrates. Higher than the last time but not that high.

 

[duanes]

I consider 25ppm to be high enough to cause an algae outbreak, especially if the tank gets even a small amount of sun. In my tanks indirect sun, and old fluorescent bulbs seemed to be the cause brown of algae and cyanobacteria, if I slacked on water changes.
You may want to double your amount of drip as an experiment to see if that helps slow down the algae.
Hard water does not necessarily mean it has lots of silica, but you could google your cities annual drinking water quality report to find out the average silica concentration.
Below is what my cities report looked like, silica is under the inorganic chemical heading
2016 Quality of Treated Water from the Water Treatment Plants