Overcrowding – no more than one inch of fish per gallon of water

Its hard, but refrain from overcrowding your tank. Overcrowding is defined as putting more than one inch of fish per one gallon of aquarium water. Some people quibble with this old rule, saying it doesn’t take into account the weight of the fish, which is a more accurate read on how much waste load the fish contributes. That’s true and they are right, but in the interest of keeping things simple the inch per gallon rule is so easy to understand and easy to follow. The fish by weight rule is not. In general, stick with the one inch of fish per one gallon of aquarium to keep your tank healthy.

The one way you can get around the one gallon of tank water to one inch of fish length is by increasing the filtration. If you have already overstocked your tank and have no way or reducing the fish load (ie, you do not want to set up a larger tank, or you do not know anyone who would take a few of your fish), then the next best thing may be to increase the filtration.

You do not need to throw out your old filter. What you are going to do instead is to get a second filter. It will need to be fairly powerful, with mechanical and biological filtration, and it should have a design that will not disrupt your tank set up too much. So underground filters are out. Power filters that hang on the side of the tank would work. And a canister filter would work, though unless your tank is over 50 gallons, adding a canister filter is probably overkill.

I recommend adding a power filter that is built for the same size tank as you have. Upgrading to a filter built for a tank larger than yours is not a totally bad idea, but because this site is focused on betta fish, and because the higher-powered power filters can create quite a lot of water currents, and bettas do not handle strong currents well, I would lean toward the most “peaceful” power filter you can get that will still substantially improve the water quality to make up for the tank having too many fish.

Ich is one of the most common aquarium fish ailments. It is so common that many pet stores put a squirt of anti-ich treatment into the water when they bag fish.

Goldfish are notorious for getting ich, but betta fish get it just as often. Fortunately ich is no big deal: It is easy to treat and rarely life-threatening. The problem is that it is extremely contagious.

What is Ich?

Ich is a parasite. Ich is actually all over the place — you can never completely get rid of it, and so long as its populations do not explode it is not a problem. When it grows to the point that we can see it on our fish, then its a problem.

The Life Cycle of Ich

This is not “must-know information”, but it will help you understand how and why you are treating your betta. Ich has three stages:
Trophozite, where the parasite has dug into the skin of your fish and you can see it as raised white spots for salt
Trophont, when the ich falls off your fish and breeds in the bottom of the tank.
Tomite, a three day period when then ich is free swimming, looking for a new host.

The only time you can effectively kill ich is in the tomite stage, when the ich are free swimming. Trophozite and trophont ich are not much affected by ich medication.

The three stages are happening simultaneously in your ich population. Even with the heat turned up, some of the ich will stay stuck in your fishes’ skin, and some are down in the gravel breeding. This is why ich treatment lasts two weeks – you have to wait until all the ich (or most… you won’t get it all) pass through the tomite stage and die.

What Ich Looks Like

Basically, fuzz or “dust” on your fish. Some bettas show it as slightly raised white spots. Some people think it looks like chicken pox on the fish. More specifically, ich may make your betta fish look like its been sprinkled with very fine salt. The “salt” may cover your fish’s entire body, or it may just be on the fins or on the head, or just in one spot. Early detection is key. This is not to say that you can not save a betta that has even advanced ich, but it is much better to catch the problem when the first little patch of ich has appeared.

The Difference Between Ich and a Fungal or Bacterial Infection

Fungal or bacterial infections can be black or white or grey. Unlike ich, they will look more like goo or cotton or even have a gel-like quality to them. Ich generally looks more like salt or dust.

It is not impossible for a betta fish to have both ich and a fungal infection, but that’s fairly rare. I wanted to emphasize this difference between fungus and ich because the treatment for the two conditions is a little different, and I’ve met a lot of betta owners who aren’t completely clear on the differences. It is not the end of the world if you do mess up the diagnosis and treat a fish with ich like it had a fungal infection, but you’ll lose precious time by misdiagnosing.

How Bettas With Ich Behave

Your betta’s behavior will probably change if it has ich. Some bettas may dart around erratically. You might see them trying to rub against things in their tank, or they may rush into things in an attempt to scratch. Other bettas may get sluggish and clamp their fins to their sides. They may stop eating and may just be lying on the bottom of the tank.

If One Fish Has Ich, They All Have Ich

First you have to realize that all of your fish gear is probably infected with ich. If you have a community tank and one fish comes down with ich, you need to assume the entire tank has ich and treat the entire tank.

*Optional first step to treatment: Do a 50% water change

So often ich outbreaks are the result of poor water quality. The water quality stresses the fish, their immune systems are weakened, and then the ever-present ich make the most of the weakened fish. Bang: You have an ich outbreak. So if you have any remote concerns that the water in your fish tank is not clean (as in, would you drink it?), then do a water change to at least give your fish a break on the bad water while they undergo their ich treatment.

Raise the Water Temperature to 85 Degrees

Do this slowly — three degrees an hour or every other hour is best. Cranking the heater from 75 degrees to 85 in one step is going to stress your betta even more, and that’s the last thing they need right now.

At 85 degrees the ich parasites will begin to let go of your fish and will become free swimming. The ich are easier to kill when they are free swimming.

Medicate

Aquarisol is best for ich, but any product that has copper or Malachite Green will work. Most pet stores will have Coppersafe, Maracide, Jungle Ick Guard or something similar. The treatment will cost you $7-12. Follow the directions on the bottle and continue to treat the ich for 14 days, even if you do not see signs of it anymore and your fish look fine. Continue to do 30% water changes every other day during the two week treatment period.

Ich Prevention
Adding a 1/4 to 1/2 a teaspoon of aquarium salt per gallon to your tank’s water is a good preventative against ich and a broad spectrum of other diseases. Only use aquarium salt — table salt will kill your fish.

If you have not been adding salt before, start with just an 1/8 of a teaspoon, then wait a week for the next water change and add a 1/4. Add the salt only to new water you put in during water changes. Do not dump 5 teaspoons of aquarium salt directly into a 10 gallon aquarium.

How To Disinfect Ich-Contaminated Fish Gear

Wash your hands with hot water and soap after every contact with your fish or fish nets or the aquarium water. If you have to disinfect a tank that had a full-scale ich plague, get a solution of 1 part Clorox bleach and 20 parts water. Soak the tank and all the other fish gear for an hour. Then scrub and rinse everything at least twice.

Bleach will kill fish. Even a whiff of it is extremely toxic to them, so if you have any doubt about there being some leftover bleach after you’ve scrubbed and rinsed twice, then scrub and rinse a third or a fourth time. Putting the fish gear out in the sun is a good way to be extra sure the last bits of bleach have been cleared.

This is a walk-through of the basic techniques around aquarium filtration and how they apply to betta tanks.

This information also applies to community tanks of all kinds, but is more focused on freshwater than saltwater tanks.

Filtration is optional for a single betta bowl

If you have just one betta in a bowl or aquarium, you don’t need to get a filter. Personally, I don’t like the noise a filter adds, and one of the finest things about keeping a betta a bowl without a filter is the silence. If you skip the filter, though, you will need to stay on top of water changes. A two gallon bowl should have a complete water change every 7-10 days. Five gallon aquariums should have 50% of the water changed once a week.

When to get a filtration system

If you’ve got a community tank, you ought to get a filter. Also, if you’ve got a lot of plants in your aquarium, you may need to get a filter to keep up with the inevitable leaf shedding and decomposing that goes along with having plants.

Having a filtration system does not mean you can skip doing water changes. You should still be removing 20% of the water from the tank every week and replacing it with treated tap water.

Also, filters need to be cleaned out every week or so. If you do not thoroughly rinse out the filter sponges and/on “filter media” your filter pump will have to work much harder and you will shorten your filter’s lifespan by 50% or more. A good-quality filter, treated well, can last ten years or more. One that’s neglected may break in 9 months.

Types of filtration

There are three kinds of filtration: biological, mechanical and chemical.

Biological filtration works by making use of the “good” or nitrifying bacteria that break down fish wastes into nitrate and nitrite. Biological filtration works with (and basically, is) the nitrogen cycle you learned about in the section on cycling your tank. Biological filtration is used in just about every filter available right now. It requires a lot of surface area, so sponges and other porous materials are commonly used to maximize the bacterial action.

Mechanical filtration means actually pulling bits of waste and whatnot out of the water. Usually this is done by running water through a sponge. Actually, the sponge is performing both mechanical filtration by grabbing the particles, and biological filtration as the little bacteria that live in all the crevices of the sponge break down the captured particles.

Chemical filtration means the filter is removing dissolved compounds from the water. Most fish filters focus on biological and mechanical filtration; chemical filtration is used only sparingly. You are kind of using chemical filtration when you treat tap water with water conditioner to get the bad gases and heavy metals out.

The only time you’d really need chemical filtration after water treatment is if you wanted to add a bag of activated carbon to your filter to absorb odors, or if you had an ammonia problem and wanted to put a bag of “ammo rocks” or “ammo-lock” in your filter. There are also nitrate and nitrite absorbing “rocks” or granules that you can put into a plastic mesh bag and then put into your filter.

If you have enough space in your betta tank (like more than five gallons – ten is better), its pretty natural to want to add some more fish. While bettas are territorial, and they may fight with any fish you put into their tank, some fish make much better (betta?) companions for bettas than others.

Here are some good choices for betta tanks. Remember… you really ought to have at least a ten gallon tank to give your betta some room, and twenty gallons is better.

1) Cherry barbs

2) Rasboras. There are many kinds of rasboras. Harlequin, scissortail, red-tailed, clown and pygmy rasboras are all good choices for a betta tank. These fish all school (except for the clown rasboras), so you should get at least six of them to keep them happy. Rasboras won’t grow larger than two inches, max, and many stay smaller than that. They are also colorful, so they’ll complement your betta’s looks. A little band of schooling fish is fun to watch and it makes a nice counterpoint to a lone betta.

3) Danios

4) Small barbs

5) Angel fish

6) Cory catfish

7) Coolie loaches
Glass catfish

This is just a starter list. Here’s how to tell if a fish would be a good companion for your betta.

Swimming habits – Pick fish that have similar swimming habits to your betta. In other words, fish that streak around near the surface of the water are going to cause problems – fish like sharks (no, not ocean-going sharks… freshwater fish called “sharks”) and hatchet fish.

Temperature needs – Choose fish that like to be kept a bit warmer than the average community tank. If your betta is happiest at 80 degrees (or at least 78 degrees), choose fish that will be happy at that temperature. Goldfish, for example, are cold water fish and probably aren’t good companions for bettas. Either your betta is going to be cold all the time, or your goldfish is going to be hot all the time.

pH needs – Bettas are pretty easy to accommodate when it comes to pH. Most standard community fishes won’t give you a problem here, but be sure to check. Discus fish, for example, like the gentle currents and warm temperatures that bettas do, so they seem like good tank mates until you consider pH. But discus like a pH around 6.5 or lower, and that’s going to be hard on your betta.

Lighting doesn’t make sense for a simple betta bowl. Some people do put their betta bowls under table lamps, or use clamp lights. If you want to add a light, that’s fine. The only need for it would be if you have plants that require brighter light that indirect sunlight. Amazon swords, for example, will need extra light, as will many vallsineras.

If you bought a java fern or java moss for your betta bowl/aquarium, you’ll probably be fine with just indirect sunlight. Java ferns and java moss are widely considered the best plants for bettas. Some betta breeders consider java moss an essential item in the breeding and fry-raising tanks. The java moss gives the female betta a place to hide, and later it does the same for the small fry. They can also eat bits of the java moss, which takes one wee bit of that part of the job off you.

For those of us who want just a simple, low to no-tech betta bowl, natural sunlight is the best choice. While it is tempting, do NOT put your betta bowl or tank in direct sunlight. The sun will overheat the bowl during the day, and then at night your betta’s water will have a severe temperature drop. Big hikes and drops in water temperature are even harder on bettas than just being cold all the time.

Direct sunlight also seems to make many bettas really twitchy behaviorally. This does make sense – they evolved to live in ditches and to hide, so they are not used to open water in full sun, but that really is only half an explanation. I don’t know the full explanation of why full sunlight stresses bettas, but it does. Keep your betta out of full sunlight.

Nice indirect sunlight is fine, though. In this sense bettas are a wee bit like ficus trees. Ficus trees can not handle direct sunlight (it burns their leaves) but they do need a fair amount of light. Bright, indirect sunlight is good. My betta, Charlie, is in a bowl that gets bright direct sunlight. There’s an amazon sword plant in his bowl (an eclipse hex 5) that is growing better than plants I used to keep under expensive aquarium plant lights. Of course, we do have algae issues (you put a bowl in even medium sunlight and it will grow algae), so I got a snail, and when I change the water in his tank I swab the inside side down with a paper towel or two. So the algae is under control, and the plant looks great.

If you have a full-scale community tank, complete with a cover, you will need some lighting, even if your tank is next to a bright window during the day. Flourscent bulbs with a plant-friendly full spectrum are an excellent choice. Metal halides are for serious fishkeepers who want to do aquascaping. A good quality fluorescent bulb will cost around $20; metal halide setups start in the hundreds of dollars.

Get yourself a nice cover for your aquarium that will accommodate not one, but two rows of lights, buy good quality flourscents, and you’ll probably be OK with most medium light plants. If you get a glass cover for your tank, you’ll also be able to add another strip of flourescents later if you want to increase the light.

Aim for about two watts of light per gallon of aquarium water and you’ll have nice lush growth in your medium light plants. Do be sure to ask before you buy plants if they require high light, then if they do, pass on that plant. Leave it to the people with the expensive metal halide setups.

After all the work you’ve gone to to create that special environment inside your tank, don’t muss it up by adding a sick fish. Here’s the rub: all new fish are potentially sick fish. Even if they look great at the pet store.

Enter the quarantine tank. This is a small tank kept in addition to your large show tank. You put all new fish in there for a week to a month (some fish people really do a month) to make sure they’re healthy before you add them into your community tank with all your healthy fish.

Quarantine tanks are also helpful for fish that become sick in your community tank. At the first sign of trouble, you take the sick fish out of your display tank and put it in the quarantine tank and treat it there.

Quarantine tanks have the usual components of other fish tanks – a heater, filter, and a backup thermometer to make sure the temperature is right. Sick tanks are kept a bit warmer than normal, as this helps the fish recover faster.

I’ve kept a lot of fish over the years, and only had a quarantine tank when I had my huge planted discus tank. Frankly, I am a bit too lazy to do the full and proper screening of new fish that quarantine tanks represent. However, there is a real risk to not having one. If you do get a sick fish in your primary tank, you are then basically dealing with not one sick fish, but an entire thankful of sick fish. If you picked up a really nasty illness or infection, there is a real chance most of your fish could die.

If you have a planted tank – live plants that you may love, that you bought expensive lights for, and lovingly tend to – the consequences are even worse. Many of the medications for even common fish diseases are not plant friendly. Neither are they filter friendly – antibiotics kill bacteria. All bacteria. If you have to use a strong dose, you may end up having to recycle your filter again, or at least build it up again from 10% of its previous capacity. It can be a real pain. (Remember why I like the no-tech single betta in a glass bowl?)

All that said, I have successfully treated ich and hole-in-the-head in a planted tank. You can still treat diseased, even in big fancy planted tanks. Its just a wee bit riskier. Still, if you take the time to really inspect your fish every day, you’ll probably catch an illness before its out of control. And that can make all the difference.

This is a very tough part of breeding bettas, and a very good reason not to breed them in the first place.

With each average betta spawn being 500 young fish, even modest culling means you’ll be killing 250 little betta youngsters. Even keeping 250 is difficult, because you’re going to have to house, feed and clean 250 bettas. If you know of the community event that needs party favors or tokens, you might be able to unload a couple dozen of your bettas there.

If possible, arrange for at least 50 new betta homes before you breed your fish unless

a) you don’t mind killing off 90% of a spawn

b) you have a very, very large fish room

c) you have a standing arrangement to sell the fish to a retail vendor

Assuming the spawn (the group of baby bettas resulting from your breeding effort, or, more precisely, your fishes’ breeding effort) is about 500 fish, and assuming you can’t possible keep more than 200 of those fish, you’re going to have to kill, or “cull” 300 fish.

To do this, you’ll first need to separate out which ones you want to keep, and which ones you don’t. For the purposes of this example, I’m going to assume all your spawn were raised together, so they can continue to be kept in the same tank.

Get two large containers. One will be for the fish you want to keep, the other for the fish you don’t want to keep. If you’re a softie like me, you may want a third tank for the fish you aren’t sure about.

Get a good light, and if necessary a magnifier glass. Get a container where you can very, very closely see each fish. You’re going to give each of those 500 fish a close once-over to weed out the losers.

The first cull can be to get rid of the sick and clearly malformed fish. These should be the ones that are clearly not nature’s favorites, and hopefully putting these guys in the cull tank won’t hurt to much. Remember – in the wild, barely in one five would survive anyway. You’ll probably lose 10-15% of your spawn in this cull.

The next cull can be to remove fish with undesirable colors and even modestly malformed fins or other body parts.

The third cull can be to weed out the remaining fish that are nice but that you just don’t have room for. This will be the hardest cut. This is when it might be good to think of local pet stores, local teachers… anyone who might be able to find homes for even some of these perfectly good fish that just quite up to your breeding standards.

To actually kill the culled fish, get a bucket and fill it half with water and half with ice cubes. The water should be extremely cold… almost cold enough to freeze on the top. Then net the to-be-culled fish and drop them, batch by batch, into the icy water. This is the easiest and most humane way to kill them. The fish will go into shock upon contact with the water, and they will be knocked out in a second or two. They won’t feel the rest. At least that’s what the medical information says.