Alright, my aquaponics system is officially shut down for the season and my goldfish are hibernating in the tub below. I want to build then a pond ultimately, but I'll get to that in a minute.
1. Do I need a filter while they are hibernating? I currently have a pump running as an aeration/deicer, but no filter. I top up the tank as it evaporates. The tub doesn't freeze solid, but it freezes over if there's no water movement.
2. Formed pond or hole+liner? What are the pros/cons of plastic liners vs fabric?
3. Pond size. I have 8 goldfish that I want to have room for in the pond-how big will I NEED for something that will be low maintenance?
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Hi! Sorry about the delay but the holidays are hectic for me!
1. It depends. On large, outdoor systems in areas that water drops below 40f, filtration isn't a 'must'. In some situations, it may even be counter-productive. Circulation, water movement and a de-icer(s) are needed though as its vital that a pond keeps an open area for gas exchange.
Ammonia levels are a balancing act in this case. Temperature (as well as ph) play a huge role here in addition to fish not being fed once the temps drop into the low 50's. Not feeding is also for health reasons as metabolism and digestion slow to a crawl and any food remaining in the body will ferment causing a host of health problems.
For your tub, I would monitor temp, ph and ammonia levels and adjust your maintenance as needed. Just make sure you have adequate means in place to prevent it from freezing (particularly if you lose power).
2. Preformed rigid plastic liners are tough but tend to run very small size. They also need to be setup perfectly level to prevent cracking/splitting from water pressure. Many people use sand, foam or even old carpeting beneath them.
Liners vary in make and material and many people use materials outside of standard pond-labeled material (such as roof liner) or build clay or cement ponds. Lined ponds do offer a lot of flexibility for design and size.
It honestly depends on your soil, climate, budget and the amount of work needed.
3. More water equals less maintenance. No different than a tank (minimally stocked, that is!). A single betta in a gallon of water will require bunch more effort than a single betta in a 50g by itself.
So, base pond estimates tend to vary a bit from 5g per inch of fish to 10g per inch of fish (on up, depending on type). These are base estimates and do not account for future growth. These estimates start off a 50-100g base (on up, depending on type of fish).
Best advice I can offer is to start big then go bigger than you think is necessary to create a nice margin of error. Remember, the likelihood that guys will eventually breed is a very real possibility, too, and that other creatures will come to inhabit your pond as well (whether you want them to or not!).
Hope this helps a bit! Feel free to ask any questions!
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