Tank Cycling Help Please

[Dwight]

I’m getting back into the hobby after several years of not keeping fish. I bought a used 10-gallon tank off Craigslist back in May and bought a brand new 20L Memorial Day Weekend.

I have tried to get these tanks cycled since setting them up and every time I think they've properly cycled, I go get fish and they die within a month. I track my parameters faithfully (sometimes obsessively) and have done everything from a fishless cycle to a fish-in cycle to actually purchasing well used filter media (which has been most successful to date) from an online fish breeder. So far I’ve lost five goldfish and six Otos in addition to a few other less expensive, common fish from Big Box Pet Store, Inc.

I currently have no fish (still waiting for parameters to settle and become consistent), my 10 gallon is planted (with Aquarium Coop purchases!) and they are doing well, just the tank has consistently increased Ammonia (typically <1 ppm) and Nitrites (typically < 1 ppm) and Nitrates vary. I do fertilize weekly. My 20-gallon has but one live plant, grows algae consistently well but still has increased Ammonia (again<1) and Nitrites (<1) with Nitrates around 10-20.

I am open to trying anything to get these tanks in condition to maintain a few fish. My goal is to keep a Betta in the 10-gallon tank, with a few tank mates and maybe some smaller cichlids in the 20-gallon. Any advice on how to accomplish this would be greatly appreciated!!

Edited November 11, 2021 by Dwight

[JettsPapa]

Welcome to the forum.  The problem may be in your fish selection and not anything related to tank conditions.  Goldfish are bred in such massive amounts, and in such concentrated conditions, that they're often unhealthy when reaching the store.  Otos are almost all wild caught, and since they often won't eat commercial foods it's not uncommon for their digestive systems to have suffered irreversible harm before reaching the stores.  I went through five once before getting one to live past 72 hours, but then that one was pretty much bullet proof.

I'd suggest try again with hardier fish, like tetras (but not neon tetras), rasboras, or danios.

[mynameisnobody]

@Dwight I agree with @JettsPapa about the conditions of the fish coming in less than stellar. Are you quarantining your incoming fish? Also, I’m not sure if you had 5 consecutive goldfish deaths or if it they were all in the same aquarium at once. The reason I say this is because 1 goldfish and you’re basically at max bioload for a 20 gallon, let alone 5 goldfish. You can build a stabler environment with time, but adding a small bioload a little at a time will vastly increase your chances of getting a cohesive environment. Personally, I’d start with danios, tetras (other than neons or cardinals) like the above post mentioned. You may just be overloading, overwhelming, and causing parameter spikes. Ps welcome to the forum. 

[HH Morant]

I think JettsPapa may be right. The water quality may not have killed your fish. 1 ppm ammonia is not going to be fatal to most fish, although I think otos are particularly sensitive.

On the other hand, a consistent 1 ppm ammonia reading is unusual. If the tank is cycled, beneficial bacteria should consume the ammonia and bring the reading to zero (undetectable). Even if your tap water contains ammonia (you might want to check it) a cycled tank would remove 1 ppm ammonia in a day or so.

You should definitely try again. As you know, there are lots of ways to cycle a tank. You might want to forgo the fertilizer until the tank is stable.

Manny's advice about stocking levels seems sound.

[Flumpweesel]

Welcome on board, you must be so frustrated.  Please don't give up. 

I had an issue once trying to just tip that last stage in a cycle get just constantly reading ammonia present, the advice I got back then was to stop trying and let the tank catch up on its own.  So I left off the water changes and l after a week (or so it was a long time ago) it did the trick. 

As you are fishless at the moment I say just do nothing and see what happens.

Andi agree with the stocking advice being some fish are just easier than others

[Patrick_G]

I think you’re on the right track with a lightly stocked 10 gallon. I like to use cycled media to “instant cycle” my tanks but of all the different ways to cycle a tank without cycled media I like the cycling with plants method from the Aquarium Coop blog. So get more plants and the one Betta, monitor parameters, do water changes when necessary and before you know it you’ll have a stable and balanced tank and you can slowly add some tank mates. 

[Endler enthusiast]

On 11/11/2021 at 10:58 AM, Dwight said:

I’m getting back into the hobby after several years of not keeping fish. I bought a used 10-gallon tank off Craigslist back in May and bought a brand new 20L Memorial Day Weekend.

I have tried to get these tanks cycled since setting them up and every time I think they've properly cycled, I go get fish and they die within a month. I track my parameters faithfully (sometimes obsessively) and have done everything from a fishless cycle to a fish-in cycle to actually purchasing well used filter media (which has been most successful to date) from an online fish breeder. So far I’ve lost five goldfish and six Otos in addition to a few other less expensive, common fish from Big Box Pet Store, Inc.

I currently have no fish (still waiting for parameters to settle and become consistent), my 10 gallon is planted (with Aquarium Coop purchases!) and they are doing well, just the tank has consistently increased Ammonia (typically <1 ppm) and Nitrites (typically < 1 ppm) and Nitrates vary. I do fertilize weekly. My 20-gallon has but one live plant, grows algae consistently well but still has increased Ammonia (again<1) and Nitrites (<1) with Nitrates around 10-20.

I am open to trying anything to get these tanks in condition to maintain a few fish. My goal is to keep a Betta in the 10-gallon tank, with a few tank mates and maybe some smaller cichlids in the 20-gallon. Any advice on how to accomplish this would be greatly appreciated!!

Hey, welcome to the wonderful hobby of fish keeping! I can definitely agree with the above posts on reviving weaker fish, or possibly maxing out you bio load. But I have one additional point to add, get fish which are suited for your water, I personally have 7.8-8.0 ph well water, and every soft water fish/ shrimp I have added to my tank have died in a relatively short period of time. So it’s always a good rule of thumb to get fish suited to your water. This can be done by asking your lfs the water parameter they keep a certain fish in, or look to google for the help. Happy fish keeping, I hope this helps

[Dwight]

Thanks for some really good replies! I've got too much invested to quit! LOL! OK, some answers/replies...

1. No quarantine as I do not have a tank flourishing yet

2. I've not put more than 2-4 small fish (small Comets + Otos) in either tank + a couple snails at any given time, trying to manage the bio load at least somewhat. I wouldn't think I'm overwhelming the tanks, but it certainly is possible.

3. 10 gallon runs clear but no algae, it's moderately to well planted, I fertilize once a week.  The 20L runs a little bit cloudy, outbreaks green water sometimes, and has no problem growing algae. Parameters have been really good for a couple weeks now, just Nitrate running high (one plant in this tank, no ferts). I clean up the green water by cutting off lights for a day or two. 

4. The fish in local Big Box Pet Store, Inc are kept in less than ideal conditions, goldfish crammed in, Otos look skinny most of the time, so I think I will change up to Tetras or Danios...oddly enough, they usually look in pretty decent shape when they have them and the tanks have been maintained. One of our stores has some pretty good fish people that seem to care. The other, not so much, but I'm still reluctant to make major fish purchases from either.

5. My tap water is town water, so it's inconsistent as it can be (especially pH and Ammonia). Before putting it in the tank, I filter it at the spigot, use Prime/Water Conditioner and let it set at least 24 hours before use.