Hi, I'm new to this forum (have been lurking and reading for a while and am blown away by how much I've learned!).
I've been keeping 2 goldfish outside in Zone 7 for 3 years. I initially started them in a 35 gallon outdoor mini pond which I didn't know at the time was too small for them. I got into this hobby mostly by way of gardening and my initial set up had a lotus, hornwort, a few marginals and duckweed. The plants and the two teeny comet goldfish thrived.
The next year, I upgraded my fish to a 50 gallon planter which they've been living in for the past 2 years now. They've both grown to about 10 inches from nose to tip of tail. Still heavily planted but now with cold hardy plants like North American frogbit, hornwort, and for marginals, horsetail rush, obedient plant, marsh marigold and a hardy water lily. There's a couple of solar fountains for aeration hooked to a rudimentary plant filter and I do 75% water changes weekly.
I am interested in scaling up my stock tank again next spring (hopefully for the last time...) in order to expand my gardening and also because based on what I've been reading here, for the welfare of my fish.
My restrictions are I live in an urban area and a lot of common fishkeeping/gardening supplies are not available in home improvement stores (things like oyster grit for increasing hardness or even large size stock tanks) unless I want to pay a large amount in shipping. I also don't have electricity outdoors and most of the land in my 1000 sq ft garden is accounted for.
I'm trying to figure out the best way to set up my new stock tank pond to avoid my previous mistakes and not make new ones.
Right now, I'm leaning towards the rubbermaid 300 gallon so I can have a lot of water gardening space.
I do not plan on increasing my number of goldfish (and my husband is keeping me to my word). I am fortunate that both fish appear male (they get breeding tubercules on their gill covers in the spring) because while they display spawning behavior all summer long, I've never seen fry so the stocking will remain 2 goldfish and maybe a handful of rosy red minnows. I'm hoping this might also mean little to no water changes as the current rate has become hard for me to maintain.
I will stick to the dinky solar pumps for aeration.
My plan is to leave the pond itself bare bottom for easy maintenance. And then to have free floating hornwort as well as frogbit on top.
Instead of having my bog plants in a separate plant filter, I'm going to buy some of those floating island planters so they can be in the pond directly.
Lastly, I plan on have 5 pots for water lilies and lotuses.
So here are my questions after that very long build up: what is the best way to pot my plants?
I thought I knew how to pot water lilies and lotuses but reading through some posts here, I'm no longer sure. My current water lily is in a 2 gallon plastic pot with no holes. It's filled with garden soil and capped with gravel. This is the recommendation of most water gardening resources and I assumed this was safe and healthy for fish. My fish will occasionally nibble the leaves or dig up the gravel but nothing excessive and usually only in the fall when I stop feeding them protein rich food and they rebel.
I've seen several posts here saying that growing in a no hole pot with soil will lead to unsafe for fish anaerobic soil conditions.
Does this mean instead of the no hole pots, I should use grow baskets or grow bags and fill them with hydroponic clay balls? If they are several inches deep, won't the hydroponic media also turn anaerobic even if water can circulate through the sides of the basket/bags?
Also, when I googled, I didn't see any hydroponic balls that are safe to overwinter. Since the plants I'm working with are cold hardy, I'd like to avoid having to break the planters down when it gets cold. Obviously the pond bottom doesn't freeze so does that mean they clay balls could safely stay out?
Also, could coco coir rated for hydroponic use be used instead (also much easier for me to source)?
Thank you for reading my longwinded post. Answers to these questions specifically or any other advice would be very greatly appreciated.
(Also, I've included photos of my current setup in case any one is curious).