ok... so you have a new tank.

and you've already put fish in it.

Your challenge over the next month to six weeks will be to keep the water from getting toxic while your biofilter bacteria get up to speed. This process is often called cycling the tank.

If you haven't gotten your fish yet, there's a better way to do it. Do a fishless cycle!

So what's going on in my tank during the first month and what are these biofilter bacteria?

Fish and the bacteria that eat debris in the tank produce ammonia which is toxic. Until your biofilter bacteria get up to speed, it's up to you to keep the water from getting toxic and killing your fish.

The first set of biofilter bacteria that will grow in your tank are the ones that convert ammonia (toxic) to nitrIte (still toxic). It usually takes the ammonia eaters 2-3 weeks to get up to speed to where they can convert ammonia to nitrIte as fast as it's produced. In the chart below, you can see that ammonia starts building up and maxes out at about a week, then starts to drop as the ammonia eaters get up to speed.

The second set of biofilter bacteria that will grow in your tank are the biofilter bacteria that convert nitrIte to nitrAte (less toxic). These biofilter bacteria start growing around week 3 and take 2-3 weeks to get up to speed to where they can immediately convert any nitrIte produced into nitrAte. In the chart below, you can see that nitrIte starts building up and maxes out at about the third week, then starts to drop as the nitrIte eaters get up to speed.

Note that after the biofilter bacteria are established, nitrAte will keep rising and in time will get to toxic levels. Regular partial water changes (and fast growing plants) will keep nitrAte at tolerable levels.

Ok. What do I need to keep the water happy?

Water test kits for ammonia, nitrIte, nitrAte and pH at minimum. Liquid tests are cheaper and more accurate than are test strips--the AP Freshwater Master Test Kit is good. You'll want a two bottle ammonia test so that it will give accurate readings when using Ammonia binders such as Amquel or Prime to make ammonia less toxic (We don't recommend Ammolock because it messes with ammonia test readings making it impossible to know what your ammonia levels are.

Amquel or Prime will help to make ammonia less toxic. If your pH is below 7.5, use Prime because it doesn't affect pH levels. If your pH is over 7.5, Amquel would be better because it detoxes more ammonia per dose than does Prime (1.2ppm vs .6ppm per dose). You can also use Amquel+, however, it may also tend to lower pH.

Salt - helps protect against nitrIte poisoning. You can use non-iodized table salt as long as it doesn't contain yellow prussiate of soda. Rock salt is cheap and works well.

A gravel vacuum or python - for doing partial water changes

Things that would make the process go faster:

• a filter pad, gravel, ornaments, plants, etc from an established disease free tank. If there's an aquarium club in your area, you may be able to find someone with some cycled media they'd turn loose of.
• Bio Spira (from Marineland) - Dr Tim did his dissertation on the biofilter bacteria and Bio Spira contains those bacteria. Current reports indicate that Bio Spira usually cuts cycling time down to 2 weeks. Sources: The Lighthouse.

Things that may help make the process go faster:

• Calcium bentonite clay - because it may contain biofilter bacteria
• Plants potted with a topsoil substrate covered with gravel. The soil contains biofilter bacteria and the plants help suck up ammonia.
• Fast growing plants (e.g. hornwort, anacharis, frogbit) because they suck up ammonia and bring some biofilter bacteria in with them.

The latter two options assume that you have enough light over the tank (at least 2 watts per gallon). Unhappy plants will add debris and can actually increase ammonia levels.

OK. So what do I do first?

The first thing to do is to draw up and dechlorinate a gallon of tap water and test it for ammonia, nitrIte, nitrAte, and pH. Why? because your source water may contain the things you're trying to keep under control in your tank. My tap water has 2.5ppm ammonia and 10ppm nitrAte. That made it more difficult to keep ammonia down at tolerable levels while my biofilter bugs were getting up to speed.

How toxic ammonia is in your tank depends on your water temperature and pH. Higher water temperature and higher pH make ammonia more toxic. If you pH is 8 you're going to have to work harder at keeping ammonia levels low than if your pH is 7. In general with:

• pH=7.0, total ammonia should not exceed 4ppm
• pH=7.2, total ammonia should not exceed 3ppm
• pH=7.4, total ammonia should not exceed 2ppm
• pH=7.6, total ammonia should not exceed 1ppm
• pH=7.8, total ammonia should not exceed .75ppm
• pH=8.0, total ammonia should not exceed .5ppm

More detailed information on ammonia toxicity, pH, and water temperature can be found here

How do I keep ammonia under control?

Test your water daily, and use a combination of Amquel or Prime and partial water changes to reduce ammonia levels to below your target levels. That way you'll have room for ammonia to increase before the next partial water change.

Base the size of your partial water changes on how much you want to reduce ammonia. e.g. a 25% partial water change will reduce ammonia from 1ppm to .75ppm (if your tap water doesn't contain ammonia). When you do partial water changes, be sure and dechlorinate and keep the change water temperature to within a couple of degrees of the tank water. When you do partial water changes, just vacuum the surface of the gravel lightly to remove debris--no deep cleaning for now. You can use an extra dose of Amquel or Prime to help lower ammonia even further.

Other things that will help:

• Make sure you're not overstocked. The larger the fish load in the tank, the more difficult it will be to keep ammonia and nitrIte at acceptable levels. The more water you have per fish, the easier it will be to keep the water happy. If you plan to cycle with fish, start off with only stocking the tank to half its capacity.
• Make sure your filter is turning over the gallons in your tank 10 times per hour.
• Feed sparingly. Goldfish are little piggies. They'll eat up what you give them and beg for more. Small meals daily or every couple of days will help slow ammonia production. High protein foods (e.g. bloodworms, tubifex worms, shrimp, etc) result in more ammonia production, so feeding things like fruits (e.g. kiwi) and veggies (shelled green peas, lima beans, zucchini, etc) will help slow down ammonia production.
• If you use Amquel you will need to keep an eye on your pH and may need to use baking soda to keep your pH from getting acidic.

Yea! I'm starting to see nitrIte. What do I do now?

If you have salt-tolerant fish, add salt at 1 teaspoon per gallon of water. Pre-dissolve in tank water and make sure it disperses well when you add it. You can use non-iodized table salt as long as it doesn't contain yellow prussiate of soda. Rock salt is cheap and works well. NitrIte is toxic. It enters thru the gills and binds up the red blood cells keeping them from being able to carry oxygen. Salt helps protect against nitrIte poisoning because it competes with nitrIte for uptake thru the gills. After you get it salted, when you do partial water changes just add 1 tsp of salt per gallon changed till nitrItes come down to 0, then you can skip adding any more salt. Your partial water changes will then remove it over time.

How do I know when my biofilter bacteria are up to speed?

When your ammonia and nitrIte are reading 0ppm and your nitrAte is rising your biofilter bacteria are up to speed. Be nice to your biofilter bacteria tho, cuz they're still touchy. They mostly live in biofilms on surfaces, so avoid disturbing them.

Always rinse your filter in discarded tank water, NOT chlorinated tap water. Be gentle at first. Later after the biofilms has matured, you can whack the heck out of the filter pad to clear it. You'll want to keep using your existing filter pad as long as you can, cuz a lot of your biofilter bacteria live there. When it's starting to get stopped up and smacking it is starting not to clear it, put a new filter pad in the tank in addition to your existing filter pad to start colonizing it.

Ya Hooooo! I'm cycled!! What now?

Give yourself a pat on the back!

and then...

NitrAte will keep building up, so do partial water changes between 20% and 40% of the tank water weekly. Keep an eye on nitrAte levels and when partial water changes don't bring them down to below 40ppm, do a second partial water change to bring them down. There is leeway on nitrAte levels. I haven't found any studies specific to goldfish, but in one study the reported amount that it took to kill half the Indian major carp tested in 24 hours was 1500ppm. I wouldn't recommend letting it even get close to that high, especially with fancy goldies--Lower is better. After your biofilter bacteria are established, if you have gravel in your tank vacuum at least half of it well during each partial water change and rinse your filter in discarded tank water.

Keep an eye on pH, especially if it's 7.5 or lower. As your biofilter bacteria convert ammonia to nitrAte they use up KH (buffers that keep pH from getting lower-acidic) and release acids which also tend to lower pH. The larger the fish load in your tank, the faster this process happens. If your pH drops below 6, it can kill both your goldies and your biofilter bacteria. If you tap water is adequately buffered (KH at or above 120ppm or 7dh), partial water changes should maintain your pH. If your source water isn't well buffered you will need to use baking soda and/or crushed shells to keep your pH from getting acidic.

and enjoy your goldies!!

They can live 10+ years if you give them a good home. :)

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