geekdragon

I see your point on how it would consume more CO2 to replace what gets gassed off at night. Cost aside though, fish might lack for oxygen, but I can't see how a steady and otherwise healthy level of CO2 would cause them undue breathing difficulties. The fish themselves should be the only natural CO2 source, and if the levels rose overmuch the controller should shut off and add no more. I wonder also if there might not be fish health benefits by avoiding a daily rise and fall in PH. Regarding the "fail safe" you mentioned, I fear that if the solenoid was stuck open, it wouldn't matter much whether there was a timer attached or not.

Isn't one of the benefits of a PH controller, that it keeps the PH (and by extension CO2) steady without the use of timers?

My magnet sits near the back and collects algae, ever since I virtually retired it. Every time I used it, I swore some new scratches appeared on the face of the tank. It didn't seem to matter how careful I was, or how sure I was to clean it first and avoid picking up grit. Whether this was all operator error or not, I eventually found a manual scraper more effective on the types of algae that plague my tank anyways (mostly green spot, BBA).

Yes, though I've heard second-hand that it's a real pain. I spoke to an employee at a local pet shop who had tried this for a customer and ended up damaging the regulator. Perhaps someone with more finesse could manage just fine. After the solenoid went bad on mine, I ended up getting the rebuild portion (cord, magnet, plunger) that goes on with four screws, rather than trying to change the whole assembly.

I'm convinced that staple food choice made the biggest difference for my fancies. They did best when I could still source Goldfish Connection ProGold pellets. My biggest scare was after an unintentional bit of overfeeding (involving children "helping"), where a Ryukin managed to be a glutton while I was cleaning the mess. He literally spent that night gasping, lying completely upside down on the bottom. I thought for sure he was dying. Back to normal in the morning.

I too have a red Tiger Lotus, and it has behaved exactly like the one the OP has. It spent about 2-3 weeks on the bottom of the tank filling out, and then dedicated itself to sending shoots to the surface. After 8 weeks, I have about 8 floating pads, and two shoots en route to the surface at any given time. This seemed novel at first, but the plant is becoming a light hog. My reading has suggested this is normal and not a result of any particular lighting/fertilizing situation. If left unchecked, they will try for the surface to set up pads and eventually flowers. If this is not desired, the shoots should be cut and discouraged to promote bottom growth. Once they find the top they are hard to retrain.