"Can you please reiterate - are you saying that any tank kept inside, away from direct sunlight is not realizing its potential? Potential for what and how? And what exactly is the algae indicating?"
That is probably the most polarizing and incorrect way to receive my post. But yes and no.
I meant that in MY opinion many of the tanks are not finished. The unused potential I was referring to are plants because I like plants and think they compliment the aquariums/ponds. I understand that most people don't like plants so the potential wouldn't even be considered. There are people on here who don't even want decorations in their tanks. Just fish swimming in glass boxes, I tried it and didn't like it. When I set up tanks and ponds, I want it to look as natural as possible.
The whole purpose right now is to test methods of maintaining temperature, dissolved oxygen, water chemistry, etc. in visually appealing ways that makes use of equipment that is already present. If I can control temp, DO and bio filtration with the one pump that is already running, why spend money on excess stuff? It is cheaper and more fun to build something more efficient than to buy overpriced aquarium equipment.
I am not saying that tanks kept indoors are not at their potential, location has nothing to do with it.
Let me simplify the purpose of them being outside with a rhetorical question. Which aquarium will become unstable and grow algae faster, one in the darkest corner of the house or one next to a window? Common sense dictates that by limiting full spectrum sun light you limit photosynthesis and put photosynthetic plants at a disadvantage to the aphotic bacteria in the bio filters. For me to test different designs, waiting for bacteria to overwhelm filters to see what isn't working would take much longer than it would for algae to bloom. It could also expose my fish in toxic levels of metabolic waste. I've been keeping mine outdoors to promote the growth of algae because I want to give algae every chance it can get to bloom when I screw up. Algae grows quickly and is very efficient (so lots of algae does not need much) at processing excess nutrients like phosphate and nitrogen compounds (the two highest demand nutrients of phytoplankton). I'll also add that nitrate and phosphate are not what I would call a toxin, it is merely a waste product of organismal and bacterial metabolism. Yes, these compounds are toxic in high concentration, but they are not produced to primarily be toxins (like curare which is a chemical defense from herbivory). We could go 'round and 'round on definitions, but that is how I classify it for practical use and admit that it is not the absolute truth. If you were to put a plant in a sealed container under a 24 hour light and pumped oxygen in, you'd kill the plant because O2 is a waste product of photosynthesis and becomes toxic in high concentrations for plants.
Now, this applies here because large fish are typically messy eaters (and inefficient metabolizers). Excess is then used by smaller organisms. The end result is waste that cannot be processed further by organisms using cellular respiration, hence the nitrate issue many people see. Most here just siphon it out and dump it down a drain and then dilute the remnants with the refill to keep the concentrations below toxic levels. I wanted to find a way to use these compounds rather than just throwing them away. I'm not trying to eliminate water changes, just use my fish to fertilize my plants just like I used animal waste to fertilize my garden. I'm making use of raw materials rather than throwing them away.
My goal is to design a highly effective system to naturally manage many aspects so that when I do go bigger and get bigger fish, I won't be struggling to keep my temps and chemistry within tolerable ranges while also using aesthetically pleasing methods...and allow me more freedom on design.
I currently have enough organisms in 130-140 total gallons to nearly fill a 1 gallon container. By using the 1 gallon per cubic inch of fish thumb rule, I'm overstocked, but my water chemistry is safe and stable, nutrient consumption is nearly complete (because of no algae), my plants look good and still with nothing more than a mechanical filter for coarse particles, an air pump and approximately 100 gph.
Here are the results of my latest water test I just finished a few minutes ago. PH is still 7.6 (my water has a very high buffering capacity so that hardly changes), ammonia, nitrite, and nitrate are almost 0 ppm. I've been busy for the last two weeks and haven't done any water changes but here is a picture to prove that I'm not spouting crazy baseless claims on nitrate.
I'm sure I mistyped somewhere in here but I'm sure you'll get the gist of what I'm doing. I'm trying to condense a bunch of information (both research and results) into one post.
