Yes. I prefer the digital timers (there are some further down that page linked) because in a power outage they have a built in energy cell that keeps the settings and the true current time for some period (I think mine are 48 hours) so you don't need to reset them or worry the lights will come on in the middle of the night when power is restored.
On the light settings, I would have the brightest/whitest light on for say 7 hours, but the before and after reduced light I would limit to 30 minutes or 60 max. The room must have light when the fish tank light comes on and goes off too, so it is not occurring during darkness which severely stresses fish. My tanks now come on at 10 am when there is good daylight filtered through the blinds into the room, and off at 5 pm when there is the same. And the fish must have a period of several hours of total and complete blackness, no room light, nothing. This replicates the tropics where every day of the year is the same, with say 10 hours of light, same of dark, and the dusk/dawn in between.
Have another dumb question, and I feel like a complete idiot asking this, but what exactly do you mean when you say "organics"? Specifically, in reference to aquariums. My mind instantly goes to decaying plant matter and fish poop, and the different bacteria that would be involved in the process, is that what you mean? I've read about decaying mulm and plant matter causing higher nitrate levels, and I do gravel vac and remove dead leaves when I find them. I figured since my nitrates never get high, that I was doing a good enough job, even if things weren't as spotless as I would like. But I don't remove every leaf that is beginning to look bad, and my water lettuce has gone through phases of boom and bust. When it's struggled, it has shed a lot of leaves that just sort of melt into the water, and there is nearly always a yellowing older leaf or two on the largest, oldest plants. Right now the plants are big and healthy, and I throw away handfuls of it most weeks. The green slime did appear on the surface when the water lettuce wasn't doing well, so is that why it appeared on the surface, but not in sheets anywhere else? Decaying floating plants, directly under the light, but not a lot of decaying plants below the surface. Different things are clicking into place and making sense now!
Organics includes all plant and animal matter that is now dead. Fish excrement, dead plant leaves, dead fish, dead snails/shrimps, decomposed fish food, etc. Most of this accumulates in the substrate and many species of bacteria (different from the nitrifiers) break it down. Ammonia is produced naturally, but also a lot of CO2. All of this feeds the plants, and the CO2 from the organics is considerably more than what comes from respiration of fish, plants and bacteria. The brown sludge that accumulates in filters, in filter hoses, in the substrate--this is decaying organic matter. Kept in check it can provide excellent food for plants, but it can easily increase to the point where it then feeds algae and cyanobacteria.
Nitrates sometimes rise indicative of increasing organics, but not always, depending upon thee system. My tanks have run in the 0-5 ppm range (API test) nitrate for over 10 years now, except for one: I had an organics bloom in my 90g tank a few years ago, and it was a mess, and nitrate was in the 5-10 ppm range. I never did track down the cause, but it persisted for three years until I tore the tank down last year when I moved. Some of the wood and plants and the few fish I kept from this tank went into a 33g, and within a few months, the organics exploded in that tank. I'm wondering if it was one of the chunks of wood. I tore this tank down too, and chucked the wood just in case.
Yes, LED lights, not the old fashioned tubes. Flat panels, one has light and blue lights, one has red (different tanks) and I think the one on this tank in question has the red bulbs, and a better quality light to my eyes, than the other one without red bulbs. They were cheap lights on Amazon, will try to find them
