Notes and Observations

• Surface scum: My preferred method of getting rid of the oily film which builds up on the surface of the water is to run an air pump with an air stone every night (scheduled by a timer). The water will be clear the next day, and the fish appreciate the aeration at night. I've used an Eheim surface suction extractor, which works as well, but it requires frequent fiddling. The black mollies I tried were not effective for me.
  
• Green spot algae (GSA): when the pressurized CO2 (24 ppm) was shut off for a couple days, the amount of green spot "algae" on the tank walls multiplied significantly. Although I have read that low phosphate levels (e.g. less than 0.2-0.3 ppm) can also trigger green spot algae, I haven't noticed this in particular. For me, low phosphate levels seem to trigger green dust algae instead.
• Excel: An overdose of Excel works to kill most algae in my tank, except for green dust algae. Start with a 5x daily overdose for the first week, and slowly reduce the dosage till you reach a minimum effective dosage. Fish and invertebrates will not be harmed.
  
• Green water: My preferred method for getting rid of green water is to use a diatom filter. I used a Vortex XL diatom filter, which works well, but it is a big hassle to use the diatomaceous earth (DE) powder. Not all DE powders are alike, you have to make sure to use a brand with a grade of DE granule size that is small enough to filter out the "green water" algae. Celite Aquacel is a brand which will work. Although the UV Sterilizer (18x Turbo Twist UVS) is much more convenient, it didn't work very well for me, and it is more expensive to purchase.
• Glosso growing upwards, not creeping along the ground: Most likely, you do not have sufficient lighting.
• Black patches/holes on java fern leaves: The nitrate levels are too low (around 0). Your nitrate test may indicate sufficient levels, but do not believe the cheap test over what the plants are telling you. Increase nitrate dosing to maintain levels of least 10 ppm, and check to see that new leaves are growing in whole. The leaves that are already damaged will not recover: trim those leaves off.
• Getting rid of Ramshorn snails: One or two Yo yo loaches will get rid of all of the small ramshorn snails. They will not be able to eat the larger snails, but you can just let the larger snails grow till they are easy to pick off, and eventually, the cycle of multiplying snails will be broken. Do they eat shrimp? I don't know, they may do so. My tank is very densely planted, so I have a hard time tracking my shrimp population, but I still have shrimp hiding out in the hairgrass. Another drawback of the loaches is that they will often uproot any plants not firmly planted deep in the substrate.
• Getting rid of ostracods: I had baby angelfish that were spawned from my mated angelfish pair, and they demolished the plague of ostracods to the point where I can't see even one. Perhaps getting one or two baby angelfish might work for you. The other fish in the tank will just mouth the ostracods and spit them back out.
• Nitrate levels: For my high light tank, having zero levels of nitrates for more than a day will cause disaster in the tank. All the plants will start melting down. Always make sure to keep your nitrate levels consistently above 5 ppm (preferably at least 10 ppm). A. reineckii, glosso and H. zosterifolia enjoy higher nitrate levels and will grow more quickly with higher levels (> 10). R. indica/rotundifolia, on the other hand, actually seem to grow more quickly (and turn pinker) with lower levels of nitrates (0 to 5). Overall, though, it is better to keep up the nitrate levels. Otherwise, it will take several weeks for your plants to recover and grow out again.
• UVS and Iron chelate: Don't run a UVS while using iron chelate. It seems to cause some chemical reaction with the fertilizers (white haze in water) which then results in severe nutrient deficiency signs in the plants. Just don't ask what the chemical reactions are.