How much water to change and how often?

I just upgraded to a 25 from a 10 and it is now officially cycled, but I have not quite been able to figure out with a cycled tank how much and how often because the tank would handle nitrites and nitrates and ammonia differently.

 

It depends on your stocking level and filtration plus lots of live plants or none. You want to keep ammonia 0, nitrites 0, and nitrates 20 or under. Even if your numbers are good i like to change 20% a week and rinse my filter media in the old tank water so you don't disrupt your bacteria.

 

For how often I'd still go for weekly, it's a classic and you can never go wrong with it. As for how much, that depends on many things:
- What fish will live there?
- How many of each species?
- How heavily, if at all, planted it will be?

The larger the fish, the more individuals, and the less planted it is, the more water you need to change, so it may range from 10 to 50 % (if you find yourself needing more than 50%, you're overstocked and should get rid of some fish).

 

30-50% weekly would be great and your fish will appreciate it

 

It depends on your stocking level and filtration plus lots of live plants or none. You want to keep ammonia 0, nitrites 0, and nitrates 20 or under. Even if your numbers are good i like to change 20% a week and rinse my filter media in the old tank water so you don't disrupt your bacteria.

I checked everything yesterday, ammonia, nitrates, and nitrites were all at zero, this is in my opinion kind of weird because I should tank change tomorrow if following the info from all of the people here!

For how often I'd still go for weekly, it's a classic and you can never go wrong with it. As for how much, that depends on many things:
- What fish will live there?
- How many of each species?
- How heavily, if at all, planted it will be?

The larger the fish, the more individuals, and the less planted it is, the more water you need to change, so it may range from 10 to 50 % (if you find yourself needing more than 50%, you're overstocked and should get rid of some fish).

I currently have
- 3 Salt and Peppered Cory Catfish
- 2 Galaxy Rasboras
- 4 Guppies
- 3 Platys

I plan to get
- 1 more Platy
- 3 more Guppies ( These are in my quarantine)

I have (Plants)
- 1 medium sized Amazon Sword
- 1 Medium sized African water fern
- 7 Baby African water ferns that kind of separated when I was moving the plant around and started growing roots, I have not put them in but I will when I think the filter will not suck them up.

30-50% weekly would be great and your fish will appreciate it

Is a 25% water change okay? I use Prime for my water.

 

You are currently lightly stocked, so yeah, I think 25% will be fine.

You should also consider getting 3 more peperred cories and at least 4 galaxy rasboras, as both of these species are shoaling/schooling and enjoy being in bigger groups. But with all of those you may be overstocked, I don't know.

 

I prefer to change 30-50 percent of the water, I do not recommend that you rinse the filter cartridges the same day that you clean the tank, once every 2 months should be enough however, filters do vary. I also don't recommend that you rinse the filter cartridge every time unless you have more than one filter, then you could do one filter one month, and the other filter the next.

I know you didnt ask, but...
Guppies and platies are not schooling fish and the number of guppies that you already have is good. Cories and rasboras are schooling fish, and a bare minimum of 6 per species is important to keep them from getting stressed.

 

I checked everything yesterday, ammonia, nitrates, and nitrites were all at zero, this is in my opinion kind of weird because I should tank change tomorrow if following the info from all of the people here!

There are reasons for doing consistent weekly water changes other than ammonia, nitrite and/or nitrate levels. Replenishing minerals in the water that are lost in time is an example.

 

There are reasons for doing consistent weekly water changes other than ammonia, nitrite and/or nitrate levels. Replenishing minerals in the water that are lost in time is an example.

I didn't fully know that but what I meant was that I was a bit suprised that I did not see a single trace of anything

You are currently lightly stocked, so yeah, I think 25% will be fine.

You should also consider getting 3 more peperred cories and at least 4 galaxy rasboras, as both of these species are shoaling/schooling and enjoy being in bigger groups. But with all of those you may be overstocked, I don't know.

That is kind of surprising! Aqvisor said I was at 123% stocked, even though I have a 40gal filter!

I prefer to change 30-50 percent of the water, I do not recommend that you rinse the filter cartridges the same day that you clean the tank, once every 2 months should be enough however, filters do vary. I also don't recommend that you rinse the filter cartridge every time unless you have more than one filter, then you could do one filter one month, and the other filter the next.

I know you didnt ask, but...
Guppies and platies are not schooling fish and the number of guppies that you already have is good. Cories and rasboras are schooling fish, and a bare minimum of 6 per species is important to keep them from getting stressed.

Thank you for your info that is very nice to know I thought Guppies an Platys were schooling fish but I still need my 3 other guppies because my 4 in the 25gal tank are pestering one another. I know I should not be making excuses but I could never find any more of my Galaxy Rasboras and my local pet store charges 9.00$ a fish and last time they were young and 3 of them did not make it and 2 were bast the three day return policy.

 

That is kind of surprising! Aqvisor said I was at 123% stocked, even though I have a 40gal filter!

You probably calculated it with the fish in quarantine. I meant right now, while the additional fish are in quarantine. Also I'm a bit skeptical on how it's calculating this one, the percentage it's adding for guppies seems disproportionate to their size...

 

You probably calculated it with the fish in quarantine. I meant right now, while the additional fish are in quarantine. Also I'm a bit skeptical on how it's calculating this one, the percentage it's adding for guppies seems disproportionate to their size...

So do you think I could fit the
- 4 guppies in quarantine
- 3 cories
- 1 Platy
-2 Galaxy Rasbras

along with what I already have?