I've had a pond not a whole lot bigger or deeper than yours for several years and I'm about the same latitude. I cut my waterfall off when I set up my halloween decorations (need the outlet anyway) unless your KOI is HUGE, I wouldn't worry about several goldfish. There are (give or take)...
The guy I share my lonely night shift is also a fish guy, and last week he was all excited about the new place he signed a lease at..
Yesterday at work I got a bit of a surprise. Apperently his lease has a nasty little clause..
NO FISH TANKS.
glad I don't live there. So his little 4' tank now...
after a couple issues with heaters, I just got in the habit of touching/feeling my tanks and canister filters as I walk buy them... after a few days, you can notice even small changes in temp or vibration indicating a potential problem...
Im not aware of any aquatic turtles regularly available in the hobby that would be suitable for a 20 gallon aquarium for any period of time.
When they are babies maybe, but plan on a tank 5-10 times that size in less than a year.
I believe in saltwater you are sealing with a different form of bacterias.... but as I still havent finished filling my saltwater tank to even start it... I am not the best person to ask.
Theres a saying I have seen on a saltwater forum that I frequent that I think is kinda applicable.
"nothing good happens quickly in this hobby"
I think those of us who 'don't do anything special' group have learned to take things slowly, most often through the school of hard knocks.
Very few...
I have thought about adding bladderwort or the like, but the tank in there isn't really set up for plants. I've decided that I like this set up, but I'm not happy the seal around the tank is leaking and I'm sure long term theres going to be a mess between the 2 tanks.
I think my next project...
Since I learned about the basics, planned out fish (OK I'm still bad about this one) and do regular water changes, I haven't had a major problem in years other than when the puppy (now 4) chewed through a filter hose and put 200 gallons of water on the floor..
I've actually used my outdoor pond for soaking wood, and occationally rock, and while it might be backwards, I seeded my outdoor ponds first filter with foam from my fish tank.
So far the only problem I have is several years ago I developed a small fuzzy 'plant' that spreads so annoyingly that...