- Joined
- Sep 25, 2006
- Messages
- 572
the reason that I suggested that you initially stock your tank with "hearty inexpensive fish" was to recommend that as a method of "cycling" your tank, not as a way of developing your aquarium keeping skills. Both of those are good things to do before you get an octopus, but some method of completely cycling your tank is mandatory. I think that you need to read several complete articles or book chapters that describe the nitrogen cycle in detail, so that you can come to fully understand it. I have some words of warning about what you might find online about "cycling" your tank:
The phrase "cycle your tank" is unfortunate, because it implies that after you watch (using test kits) the ammonia level rise, and then fall, over a period of days, followed by the nitrite level rising, and then falling (those two events constitute a "cycle") that your tank is ready for animals. A better term than "cycle" would be "grow a colony of denitrifying bacteria that is large enough to consume all of the waste my animals will produce per day". You see, at the end of a "cycle" you will have grown a population of denitrifying bacteria, but it might be a small population. The bacteria multiply in numbers until they run out of either "food" (animal waste) or surface area to live on (the pours on the surface of live rock for example). Assuming you've supplied enough surface area to live on (live rock (1 to 1.5 pounds per gallon?) or other bio-filter media (like the sponges in an Aqua-Clear hang-on filter) with good water flow over it's surface) you need only to supply a steady daily amount of animal waste for the bacteria colony to eat. Over a period of a week or two (or five) the bacteria colony will reproduce (or die off) and stabilize at a population level that matches the amount of food available. When your ammonia and nitrite levels measure consistently at zero, you will know the population size has stabilized to match the amount of waste that is entering the system every day (that marks the end of a cycle). The reason I suggested that you keep a few tough inexpensive fish after your first "cycle" is so that the fish will provide a steady amount of fish poop every day to keep your bacteria colony alive and fed. It's not a lot of fun for the fish to live in a tank while the ammonia and/or nitrite levels are above zero, but if they are tough, they'll get through it, and if they are cheap, you won't go broke if some of them ie along the way (I know, this is a harsh method, but it works, and I'm okay with it). After the ammonia and nitrite levels stabilize to match the rate of incoming fish poop, you can add another fish. That will increase the amount of poop per day beyond what the bacteria colony is able to handle, which will start another little cycle (rising, then falling levels of ammonia, and then nitrite) as the bacteria colony multiplies and grows enough to match the new higher amount of available food (fish poop). Then, after the ammonia and nitrite levels stabliize again, you add another fish (or two), and measure, and wait, and after a days/weeks, the levels will stabilize again. You keep doing this process of adding fish, and waiting until for the next little cycle to finish, until the amount of waste that your total population of fish is producing per day, is roughly equal to, or greater than, the amount of waste that you expect your octopus to produce (assume that an octopus produces about 1.5 times as much waste as an equal weight of fish would produce). Then, remove all the fish, and put your octopus in the tank, all on the same day. The octopus waste will replace the fish waste as a source of food for your colony of denitrifying bacteria, and since the size of the colony is already large enough to handle at least that amount of waste, your octopus wont' have to live through another cycle (toxicly high ammonia and nitrite levels). Get it? Just "cycling" your tank is not enough. You need to increase the amount of animal waste per day, which will trigger a series of cycles, until your bacteria colony is large enough to deal with all the octopus poop (and uneaten food, etc) that your octopus will produce per day. Most descriptions of how to cycle your tank don't explain that, and it's easy to miss the point of cycling, and put sensitive animals like octopus through a potentially deadly cycle (ammonia spike).
I didn't mention it, but you need to also test for nitrate (in addition to ammonia and nitrite) and do regular (weekly?) partial water changes to keep the nitrate level below 15 (and eventually below 10). So you need to buy at least these three test kits to be able to "cycle" your tank. You'll need to work out a procedure of doing regular partial water changes, and a routine for water testing, and other regular tank maintenance. It can take a while for many people to get these habits and procedures worked out, and until you get good at doing these things on schedule, without fail, your animals might have to live through some hard times. That is why Tonmo people recommend that you get some marine aquarium experience before you get an octopus. That way you can make your mistakes and learn the ropes without risking expensive delicate animals like octopus (and without getting discouraged as a result). So, after you get all finished with all the little cycles, and you are ready to swap your large population of hearty inexpensive fish out and put an octopus in, consider waiting on the octopus, and instead getting some other, less expensive, inverts to practice on as CuttleGirl suggested.
The phrase "cycle your tank" is unfortunate, because it implies that after you watch (using test kits) the ammonia level rise, and then fall, over a period of days, followed by the nitrite level rising, and then falling (those two events constitute a "cycle") that your tank is ready for animals. A better term than "cycle" would be "grow a colony of denitrifying bacteria that is large enough to consume all of the waste my animals will produce per day". You see, at the end of a "cycle" you will have grown a population of denitrifying bacteria, but it might be a small population. The bacteria multiply in numbers until they run out of either "food" (animal waste) or surface area to live on (the pours on the surface of live rock for example). Assuming you've supplied enough surface area to live on (live rock (1 to 1.5 pounds per gallon?) or other bio-filter media (like the sponges in an Aqua-Clear hang-on filter) with good water flow over it's surface) you need only to supply a steady daily amount of animal waste for the bacteria colony to eat. Over a period of a week or two (or five) the bacteria colony will reproduce (or die off) and stabilize at a population level that matches the amount of food available. When your ammonia and nitrite levels measure consistently at zero, you will know the population size has stabilized to match the amount of waste that is entering the system every day (that marks the end of a cycle). The reason I suggested that you keep a few tough inexpensive fish after your first "cycle" is so that the fish will provide a steady amount of fish poop every day to keep your bacteria colony alive and fed. It's not a lot of fun for the fish to live in a tank while the ammonia and/or nitrite levels are above zero, but if they are tough, they'll get through it, and if they are cheap, you won't go broke if some of them ie along the way (I know, this is a harsh method, but it works, and I'm okay with it). After the ammonia and nitrite levels stabilize to match the rate of incoming fish poop, you can add another fish. That will increase the amount of poop per day beyond what the bacteria colony is able to handle, which will start another little cycle (rising, then falling levels of ammonia, and then nitrite) as the bacteria colony multiplies and grows enough to match the new higher amount of available food (fish poop). Then, after the ammonia and nitrite levels stabliize again, you add another fish (or two), and measure, and wait, and after a days/weeks, the levels will stabilize again. You keep doing this process of adding fish, and waiting until for the next little cycle to finish, until the amount of waste that your total population of fish is producing per day, is roughly equal to, or greater than, the amount of waste that you expect your octopus to produce (assume that an octopus produces about 1.5 times as much waste as an equal weight of fish would produce). Then, remove all the fish, and put your octopus in the tank, all on the same day. The octopus waste will replace the fish waste as a source of food for your colony of denitrifying bacteria, and since the size of the colony is already large enough to handle at least that amount of waste, your octopus wont' have to live through another cycle (toxicly high ammonia and nitrite levels). Get it? Just "cycling" your tank is not enough. You need to increase the amount of animal waste per day, which will trigger a series of cycles, until your bacteria colony is large enough to deal with all the octopus poop (and uneaten food, etc) that your octopus will produce per day. Most descriptions of how to cycle your tank don't explain that, and it's easy to miss the point of cycling, and put sensitive animals like octopus through a potentially deadly cycle (ammonia spike).
I didn't mention it, but you need to also test for nitrate (in addition to ammonia and nitrite) and do regular (weekly?) partial water changes to keep the nitrate level below 15 (and eventually below 10). So you need to buy at least these three test kits to be able to "cycle" your tank. You'll need to work out a procedure of doing regular partial water changes, and a routine for water testing, and other regular tank maintenance. It can take a while for many people to get these habits and procedures worked out, and until you get good at doing these things on schedule, without fail, your animals might have to live through some hard times. That is why Tonmo people recommend that you get some marine aquarium experience before you get an octopus. That way you can make your mistakes and learn the ropes without risking expensive delicate animals like octopus (and without getting discouraged as a result). So, after you get all finished with all the little cycles, and you are ready to swap your large population of hearty inexpensive fish out and put an octopus in, consider waiting on the octopus, and instead getting some other, less expensive, inverts to practice on as CuttleGirl suggested.