How Much Water To Change After Tank Is Finished Cycling?

[Jason1039]

Hello all this is my first post so bare with me here.

I'm new to the aquarium world so I have a few questions

I started cycling my 10gal betta tank over 2 months and 2 weeks ago. I am doing a fishless cycle with pure ammonia and my ammonia was dropping from 4ppm to 0ppm in about 12hours so I would dose it back to about 3ppm everytime it dropped to 0. My nitrites were off the chart for about a week, and just yesterday my nititres dropped to 0 with my api master test kit showing my nitrates were 80-160ppm.I do believe my cycle is about 95% finished. How ever I know that the only way to lower nitrates is to do a big water change. So my questions are...

1)How much percentage of water do I have to change? Some people have told me not to do more than a 70% water change or I will kill off the good bacteria. Is this true? Should i do about 90%?

2)Is it ok do a light gravel vac with the water change? During the cycle i have noticed a thin layer of slime on some of the surfaces in my tank (mostly the gravel) and I wanted to just vacuum the very top layer of gravel before adding my betta. Not really digging deep into the gravel.

3) Can I rinse my filter foam in the old tank water when I do the water change? It has gotten completely filled with that slimy stuff.

4) How do I acclimate my betta in the new 10g tank? He is not coming in a bag or cup from the pet store. I've had him in a 2.5gal for over a year now and I've thrown out his cup a while ago.

Thanks in advice and sorry for all the questions

 

[fluttermoth]

Welcome to the forum, and well done on deciding to do a fishless cycle

1. As long as the new water is warmed and dechlorinated, you can do as large a water change as you like. Personally, I'd drain the tank right down to the substrate (don't forget to switch your heater and filter off if you do this!). You won't lose many bacteria, as they cling onto surfaces, not float around loose in the water.

2. Yes, it's fine to do a gravel clean as well.

3. Yes, you can clean the filter sponges as well. The slimy stuff is a kind of algae that's very common in new set ups and, whilst it's unsightly, it's not harmful.

4. You'll need some sort of container; an old ice cream or margarine tub is what I use. Put your betta in that, with some of his old tank water, let it float and gradually tip it, letting the old and new water mix for a while before you let him swim out. As both tanks are filled from your water supply, they should be very similar, but do a big water change in the old tank, as well as the new one before you start, so the two waters are as similar as possible

One last point; as you've cycled to 3ppm, you will have plenty of 'spare' bacteria (one betta is not going to produce anywhere near 3ppm of ammonia!), so if you do lose a few, you needn't worry.

Also, don't feed your fish for a day or two when you do the move, and keep testing daily, in case of any spikes, unlikely, but they can happen; if they do, you'll just need to do one or two extra water changes while the bacteria settle down.

 

[Gruntle]

Turn the filter off and suck the tank right down to the gravel (or as close as possible). That should give you around a 90% change (there will be some water in the filter and some in the substrate) so if your nitrates are now at 160ppm they'll drop to 16ppm.
 
I think you can assume the vast majority of your bacteria will be clinging to the media in your filter so you won't lose them. Just make sure your water is dechlorinated before adding it, then when you switch your filter back on, there won't be any loss of bacteria.
 
And everything fluttermoth said is true too. I'm just reinforcing it.

 

[Jason1039]

Thank you both for your responses. I did about an 80%(a little less than 90%) water change yesterday, and then i waited for the tank to settle. The next day i tested the water again. When i did the tests showed up as this:

Ammonia =.25ppm
Nitrites = 1ppm
Nitrate =40-80ppm

I wonder if i maybe stirred up the gravel too much and caused a mini cycle because my ammonia and nitrites were both zero, before the water change.

I'm still waiting for the ammonia and nitrites to drop to zero before doing another water change to lower the nitrates.

 

[Jason1039]

Welcome to the forum, and well done on deciding to do a fishless cycle

1. As long as the new water is warmed and dechlorinated, you can do as large a water change as you like. Personally, I'd drain the tank right down to the substrate (don't forget to switch your heater and filter off if you do this!). You won't lose many bacteria, as they cling onto surfaces, not float around loose in the water.

2. Yes, it's fine to do a gravel clean as well.

3. Yes, you can clean the filter sponges as well. The slimy stuff is a kind of algae that's very common in new set ups and, whilst it's unsightly, it's not harmful.

4. You'll need some sort of container; an old ice cream or margarine tub is what I use. Put your betta in that, with some of his old tank water, let it float and gradually tip it, letting the old and new water mix for a while before you let him swim out. As both tanks are filled from your water supply, they should be very similar, but do a big water change in the old tank, as well as the new one before you start, so the two waters are as similar as possible

One last point; as you've cycled to 3ppm, you will have plenty of 'spare' bacteria (one betta is not going to produce anywhere near 3ppm of ammonia!), so if you do lose a few, you needn't worry.

Also, don't feed your fish for a day or two when you do the move, and keep testing daily, in case of any spikes, unlikely, but they can happen; if they do, you'll just need to do one or two extra water changes while the bacteria settle down.

 
 

Turn the filter off and suck the tank right down to the gravel (or as close as possible). That should give you around a 90% change (there will be some water in the filter and some in the substrate) so if your nitrates are now at 160ppm they'll drop to 16ppm.
 
I think you can assume the vast majority of your bacteria will be clinging to the media in your filter so you won't lose them. Just make sure your water is dechlorinated before adding it, then when you switch your filter back on, there won't be any loss of bacteria.
 
And everything fluttermoth said is true too. I'm just reinforcing it.

Thank you both for your responses. I did about an 80%(a little less than 90%) water change yesterday, and then i waited for the tank to settle. The next day i tested the water again. When i did the tests showed up as this:

Ammonia =.25ppm
Nitrites = 1ppm
Nitrate =40-80ppm

I wonder if i maybe stirred up the gravel too much and caused a mini cycle because my ammonia and nitrites were both zero, before the water change.

I'm still waiting for the ammonia and nitrites to drop to zero before doing another water change to lower the nitrates.