Setting up a cycle in tank with fish in it

[Atriz1]

So I learned about the importance of having a proper cycle after I had got some fish and a snail. Currently in my 20 gallon tank, I have a angel fish and a molly, and a snail, with one plant.

I am unsure of how to set up the cycle now, however. Mostly of what I see is doing it fishless at first, or with hardy fish. This tank has been running for about half of a year now too. I don't want to hurt my fish (especially since my white molly has an edge of black on her dorsal fin? It does't look like tail rot to me)

Also, I have a salt water tank I take care of, how would I go setting up a cycle in there with fish already in there?

(I really wish I researched fish care before getting them)

I have a ammonia, and a nitrate tester. Along with a filter in all of my tanks.

I tried researching this, but for some reason I am just confused about it. I understand the science behind it, the Ammonia breaking down, etc, and how nitrate is safer (but not good) for fish. Its just setting it up that is confusing me. Thanks!

 

[sinibotia]

If the tank has been running for half a year and the fish are still alive, then it's already cycled in that time! Cycling is "set up" when you provide a source of ammonia- which you did when you added the fish. It happened without you knowing!

 

[Atriz1]

Its a relief to know that it has been set up without me doing anything, but I have had fish deaths before, my angel fish is the only one that has been there from day one (my snail was added about two months after) But I haven't had one in about two and a half months. (though most of my fish deaths were related to fish aggressiveness that I didn't catch soon enough). I think the last one that something had happened maybe related to cycling, is when I went on a weekish trip, back in late July, (after changing their water), I had added a feeder block and I came home to two fish completely gone, and a chiclid acting really strange (unfortunately, he didn't make it). I am not sure if they didn't like the feeder block or something had happened when I wasn't there to see it.

I am confused as to when to change my water, or when to rinse through my filter because I saw that rinsing through your filter can disrupt the cycle? Should I make it a set thing of how much water I take each time? I have been changing about 25-40% of the water about every week, and making sure to stir up the gravel on the bottom so some of the trapped food and other stuff will be re exposed to the filter.

Also, should I add a air stone when I have a bubbler already in that tank?

Thank you again!

 

[sinibotia]

I would guess that the feeder block fouled the water and caused your fish deaths. If your fish didn't eat it it probably created ammonia so yes, in a way it was cycling related.

Your water change schedule is fantastic! 25-40% weekly is perfect. I do almost exactly that. (I do 50-75% but I have heavier stock and am a perfectionist).

As for filter cleaning, just rinse your filter cartridges in tank water after you remove it during a water change and then place it back. That will keep the bacteria in your filter alive without your filter getting clogged.

You don't need an air stone, but they don't hurt if you like them.

 

[Atriz1]

Will this be any different for a salt water tank? The one that we have is a 85 gallon with 2 tangs, a foxface, two clownfish, and a snail. I do weekly changes, about 40% on average, and always add a pH substance to bring it up to 8.3.

Thank you so much, this is a huge relief to me.

 

[sinibotia]

I'll be honest, I have never had a saltwater tank in my life. I love freshwater tanks too much! You'd be better off asking in the saltwater section of this board!

 

[Atriz1]

Will do! And I agree, freshwater are better than saltwater in my opinion but a family member wanted a salt water tank so now I take care of it for her. Thank you again for all the help!

 

[CleverBs]

The saltwater cycle is the same as freshwater. If it's had fish in it over a month it cycled itself. 40% water changes is over kill. Leave it at 20%. My concern is why you need to buffer the ph to get it to 8.3. You don't have enough rock in the tank of thats needed. Also unless it's a reef tank you don't need to worry much about the ph. Just let it settle at whatever's stable in the tank. It will probably be stable at about 7.8-8.0