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MyraVan · 02-21-2007, 04:48 AM

OK, you say the tank wasn't cycled, so let's assume you're starting from scratch, so the fact that you're using old filters doesn't matter: they are old filters with no useful bacteria. So here's my go at your questions:

Q1. Should I plant my tank before or after the cycle?

I feel you should plant your tank up straight away. Plants need time to establish themselves, and the sooner you get going with it the sooner you'll have that nice aquatic garden you're looking for.

Q2. How long should I leave the decomposing shrimp in the water?

I have never used the rotting shrimp method, but I'd say that once your ammonia and nitrite levels are 0, then you can add the fish. I would remove the rotting shrimp at the same time as you put the fish in: that way it will continue to provide food for your bacteria until the fish can do the job.

Q3. If I do add plants when the tank is cycling, will the nitrogen cycle be different and require a different set of rules?

The cycle will probably be different, mainly because healthy growing plants will absorb ammonia directly out of the water (they use it for fertilizer), leaving less left over for the bacteria in your filter. Thus the bacteria in your filter (and on all the surfaces of the tank, really, but more so in the filter) will end up growing slower, or else you will end up with less of them. I don't feel that this is a bad thing; after all your plants will continue to stick around and will continue to help deal with the fish wastes. To be honest, unless you've got very fast growing plants, they won't absorb much ammonia to start with, since plants need time to establish themselves before they really get growing. So just do the cycle using the usual rules. If you get no ammonia reading at all then either (a) you've got some very fast-growing plants, or (b) your test kit isn't working.

Q4. About how long would the cycle take with a 29g aquarium?

No set answer here, just keep testing. I've heard a max of about 6 weeks.

Q5. Is it ok to replace the filter media, if so, should I do this after the cycle or can I do it while its cycling, like when I have the money for a new filter? (seeing as I am going to purchase a better filter, and one filter that is so I dont have to have 2 going)

Assuming that you're plants aren't growing fast enough to eat up all the ammonia, then you're going to be growing lots of good bacteria in your filters. Now, plants themselves have alot of surface area, so they will also have some good bacteria on them. There wil be more on your filter, but there will still be some elsewhere. If you simply take out all your filter media and replace it with new, you will lose all the good bacteria in your filters. You'll still be left with what's left on the plants and gravel and such like, and the plants themselves will absorb some ammonia, but will it be enough to support your full fish load? Maybe not; it's not worth the risk.

However, you normally don't have to replace all your filter media at once, even if you have a completely different filter. You take the filter media out of your old filters and put it into your new filter. You might have to cut it up to do this, but that's OK; it won't hurt the bacteria. Just make sure it doesn't stay out of the water too long and you don't clean it with tapwater (or detergents or anything like that) because that will kill the bacteria. If you do that, then it's fine to cycle with your existing filters and then replace them later.

Q6. And should I add salt while the aquarium is cycling or after? What about the plant food and fertilizer....if I have plants at that time will it mess up the cycle?

Er, what's the salt for? Will this be a brackish tank? Or will you be keeping livebearers like mollies, that like a very low level of salt? If not, then don't add salt. If this will be a brackish tank or a tank for livebearers, then add the salt at the beginning, but be warned that many plants don't like salt and may die. As for plant food and ferts, as long as the plant food doesn't have any ammonia, nitrite, or nitrate then it will be fine to add during the cycle. No plants foods should have ammonia or nitrite, but some may have nitrate.

02-21-2007, 04:48 AM	#4
MyraVan Senior Member Join Date: Jan 2005 Location: Cambridge, UK Posts: 861	OK, you say the tank wasn't cycled, so let's assume you're starting from scratch, so the fact that you're using old filters doesn't matter: they are old filters with no useful bacteria. So here's my go at your questions: Q1. Should I plant my tank before or after the cycle? I feel you should plant your tank up straight away. Plants need time to establish themselves, and the sooner you get going with it the sooner you'll have that nice aquatic garden you're looking for. Q2. How long should I leave the decomposing shrimp in the water? I have never used the rotting shrimp method, but I'd say that once your ammonia and nitrite levels are 0, then you can add the fish. I would remove the rotting shrimp at the same time as you put the fish in: that way it will continue to provide food for your bacteria until the fish can do the job. Q3. If I do add plants when the tank is cycling, will the nitrogen cycle be different and require a different set of rules? The cycle will probably be different, mainly because healthy growing plants will absorb ammonia directly out of the water (they use it for fertilizer), leaving less left over for the bacteria in your filter. Thus the bacteria in your filter (and on all the surfaces of the tank, really, but more so in the filter) will end up growing slower, or else you will end up with less of them. I don't feel that this is a bad thing; after all your plants will continue to stick around and will continue to help deal with the fish wastes. To be honest, unless you've got very fast growing plants, they won't absorb much ammonia to start with, since plants need time to establish themselves before they really get growing. So just do the cycle using the usual rules. If you get no ammonia reading at all then either (a) you've got some very fast-growing plants, or (b) your test kit isn't working. Q4. About how long would the cycle take with a 29g aquarium? No set answer here, just keep testing. I've heard a max of about 6 weeks. Q5. Is it ok to replace the filter media, if so, should I do this after the cycle or can I do it while its cycling, like when I have the money for a new filter? (seeing as I am going to purchase a better filter, and one filter that is so I dont have to have 2 going) Assuming that you're plants aren't growing fast enough to eat up all the ammonia, then you're going to be growing lots of good bacteria in your filters. Now, plants themselves have alot of surface area, so they will also have some good bacteria on them. There wil be more on your filter, but there will still be some elsewhere. If you simply take out all your filter media and replace it with new, you will lose all the good bacteria in your filters. You'll still be left with what's left on the plants and gravel and such like, and the plants themselves will absorb some ammonia, but will it be enough to support your full fish load? Maybe not; it's not worth the risk. However, you normally don't have to replace all your filter media at once, even if you have a completely different filter. You take the filter media out of your old filters and put it into your new filter. You might have to cut it up to do this, but that's OK; it won't hurt the bacteria. Just make sure it doesn't stay out of the water too long and you don't clean it with tapwater (or detergents or anything like that) because that will kill the bacteria. If you do that, then it's fine to cycle with your existing filters and then replace them later. Q6. And should I add salt while the aquarium is cycling or after? What about the plant food and fertilizer....if I have plants at that time will it mess up the cycle? Er, what's the salt for? Will this be a brackish tank? Or will you be keeping livebearers like mollies, that like a very low level of salt? If not, then don't add salt. If this will be a brackish tank or a tank for livebearers, then add the salt at the beginning, but be warned that many plants don't like salt and may die. As for plant food and ferts, as long as the plant food doesn't have any ammonia, nitrite, or nitrate then it will be fine to add during the cycle. No plants foods should have ammonia or nitrite, but some may have nitrate.