Backyard Aquaponics
A place to discuss aquaponics

Sometimes it's normal and sometimes having the fish get close to the air source like that can be an indication of a lack of oxygen or that they are having troubles getting oxygen if it's there - other times fish just seem to enjoy it or they're just hiding in the bubbles. I can't be certain but I doubt your fish are having problems getting oxygen but if you see them gasping at the surface or they seem lethargic then you should be concerned.

Try using a sponge filter with your air pump. That way you're getting filtration, aeration, and water movement all with just an air pump.

Are there plants I can add to the water that filter the water? What would be the best for that? I'll check out the sponge filter.

Horsetail - very fibrous rhizome runners that have plenty of air pockets. This is pre-historic plant, that has many medicinal properties to it. Very easy to propagate from root divisions.

The one baby goldfish is blackish and hides throughout the day almost. The second is a golden baby goldfish that hides a lot less. Hmmm..

You need to clean the uneaten food out of your tank and feed less. In a small system, uneaten food can degrade your water quality very quickly. If your water quality is bad, then your water won't hold enough diffused oxygen for your fish no matter how many bubbles your pump makes.

I used vitamin C (calcium ascorbate) tablets (1g) to clean the water of chlorine. I added the VC to the water and I let it sit for days prior to adding fish. I know about acidity and fish and such but the VC should quickly degrade to ammonia and other byproducts which could kickstart the bacterial process. I then added stones from outside which should bring in the right bacteria and allow the fish to hide. The calcium in the VC fell to the bottom and has been staying there for a while. Very interestingly the fish food sticks to the calcium clumps at the bottom (it's very little calcium, probably some magnesium in there and other fillers lol) like magnets that are attracted to each other, and the fish eat the fish food. The aquarium is a plastic case that has a wide and long surface area but is not too deep (being a problem for aeration I know, but I am working on a plastic aquarium with the exact opposite qualities, very deep but little surface area).

Hmm, actually shallower tanks and greater surface area is a good thing for diluted oxygen, not bad, so I wouldn't worry about that. Its definitely true that you don't want lots of un-eaten food lying around. It's a shame that goldfish cost a lot over there, here in spain mine cost me 1.50€ each. I would say that the key thing is to be very patient and sparing with food in the early stages when you are not sure you are cycled yet, especially in a small system. If your fish look unhealthy, do water changes with de-chlorinated water. You don't need to add anything to the water to do this (unless it has "chloramine" i believe?), just let it sit, uncovered and with as much surface area as you can conveniently arrange, ideally in the sun, approx 24 hours. The bacteria turns up, even indoors, maybe just leave closet door open every now and then.

What lights have you got?

No lights.. yet. I assume aquarium lights are only for humans unless we're talking special fish or other aquarium additions like plants.

Aquarium lights are usually designed to promote growth in the aquatic plants, so yeah they would be a good choice, there are cheaper options though.

But fish (or at least most fish, especially goldfish) don't require light? So if I don't get plants and I don't plan on having my fish for show then it doesn't matter?

My plan is to seal my aquarium off from any light source and then have my plants on top of the aquarium with a light source at the uppermost top.

Ok I think we had a misunderstanding! I was asking about what lights you have for your plants, on top of the aquarium, not in the aquarium.

I tried making an aquarium filter several times by using gravel (also tried plastic bits) and a small coca cola plastic bottle but it doesn't seem to work (actually one time it may have worked ever so slightly) because particles do not seem to want to move... there's no "suction" happening.
I tried using a small pvc T and U-shaped pipe and it did indeed seem to create the right kind of current but I couldn't really figure out how the heck I was going to make it work correctly unless I somehow fitted the pvc pipe to the plastic coca cola bottle so the water would flow into it.. perhaps I'll try that later...
Maybe it's just very weak the current it creates and I need to let time tell if it works?

Are the bubbles supposed to move the water in the right direction? Well, how on earth do you ensure that the suction holes (or suction hole if singular) don't spew out water but instead take it in?

Does having a water current meant that the solids at the bottom are in movement constantly or does it mean that a ripple effect (like when a drop of water falls on a pool of water) is at the water surface? Because my aquarium does have a decent but mild ripple effect, although it does nothing to the solids at the bottom.

Can anyone link me to a tutorial on how to make a filter (that actually works) with an air pump alone? I'm interested in the water suction effect, not in the filter medium.

I'm sure there are videos out there, but personally I wouldn't bother... no need. My FT has gravel at the bottom and after 2 months is still no where near needing a clean, and when it does, its gonna be a fairly simple and easy job using a tube to siphon off gravel to rinse and return.