Breeding Egg-Laying Aquarium Fish, Part Three: Environment
This is the third in a series of articles on breeding egg-laying aquarium fish. In Part Two, we discussed why you want to become skilled at hatching and harvesting brine shrimp. (Hint: your babies need to eat!)
This article deals with the environment you should provide your fish to help induce spawning, and successfully raise the resulting baby fish.
As explained in Part One, we are going to prepare a “species-only” tank, which will be the home of the particular fish we want to breed. I recommend 10 gallon tanks, because they are cheap, readily available, and easy to pick up, and thus clean.
Notice I said tanks. Yes, you can successfully breed egg-layers using only one tank, but it is easier with two or more. The simple reason for this is that more than one tank allows you to separate the adults from the fry.
This is going to sound heretical to some experienced aquarists, but I do not use heaters in my tanks. If you’ve ever had a heater fail, you’ll know why – boiled fish! Besides, I like to keep my tanks simple, with as few electrical devices as possible. Many tropical fish are comfortable at the same temperatures we are, so supplemental heat is unnecessary. However, if you live in a cold area, or like your house to be kept at 60 degrees, you may want to get a heater for your tank. It’s up to you.
You’ll probably want a basic lighting fixture, or hood, for your tank, although I have also just used a piece of glass with a portable florescent light placed on top of it. Note that if where you live aquarium hoods using incandescent bulbs, (and the incandescent bulbs themselves!), are still available, these fixtures give off a lot of heat, which would be yet another reason to pass on putting a heater in the tank.
Whether you want a filter or not is also up to you. Just bear in mind that without a filter you’ll be changing the water in the tank much more often. I used to not use filters, conditioning large amounts of water in a big plastic trash can, (which was bought specifically for this purpose), by letting it sit for a day or so, and making frequent water changes. These days that is too much work for me, so I use power filters that hang on the back of the tank. Also bear in mind that if you live in the USA, you probably have chloramine in your water, which persists longer than chlorine. (Neither of these is all that great for you either, by the way, but both are preferable to drinking contaminated water.) At any rate, you should accept that you will need to treat your water with a conditioner designed to make tap water safe for fish. The days of knowing you could simply leave water sitting out overnight to let the chlorine escape are gone.
Water hardness? pH? You can mess with those if you want to, but this is supposed to be a beginner’s guide. I personally have never ever tested my tanks for water hardness or pH, and I have kept, and bred, mollies in the same tank as corydoras. (Don’t do that, at least starting out. Give the Corys their own tank!) My advice for you is to start out with fish that will acclimate to your water, whatever its composition, then as you have more experience try your hand at those fish who require more exact environmental conditions, (e.g., many dwarf cichlids). But by all means …. if you have the desire to “fine tune” the water in your fish tank, don’t let me dissuade you!
The bottom of the tank should be bare, or covered with marbles. If you prefer, you could use those decorative stones they sell in craft stores. Just be sure you aren’t introducing a toxic material to your tank.
I like to grow one or more plants in the tank. Amazon swords work best for me, though most of them do get a bit too large for a 10 gallon tank. I grow all my plants in small pots. First I line the drainage holes in the bottom of the pots with landscape fabric, which in theory will let only water out. Then I put in about an inch or so of gravel. Next, I do what everyone will tell you not to do: I put some soil in the pot. (Yes, some of the dirt will manage to leak through the landscape fabric and out the bottom of the pot.) I then place the plant in the pot, and start covering its roots with gravel. I top off the pot with a quarter inch or so layer of sand.
Plastic plants are good too, and the more finely-leaved types will provide good hiding places for the fry, so they won’t become one of the adult fish’s meal. Just be sure that the plastic plants you select are actually designed for aquarium use. I once killed off a whole tank of zebra danios by putting into their tank plastic plants I had bought at a discount store. These plants had a metal core, (used to position them for decorating, I suppose), which eventually began to rust and release toxins.
Finally, I allow some algae to grow on the sides and back of the tank. (The front I keep clear.) This, along with the potted plants, will be our “infusoria insurance”. I still think infusoria never lives up to its hype, but in case our brine shrimp hatcheries all suddenly fail, we can hope that the presence of organisms living off the algae and potted plants will be enough to pull a few of the fry through.
Okay, now that we’ve got our brine shrimp hatching, and our aquariums set up, let’s move on to Part Four, where we’ll discuss some of what I consider are the easiest egg-laying fish to spawn.