Can't get tank to cycle

[LeoSpaceman]

Hi everyone, I've been working to get a 20 gallon tank to cycle with no luck for about 3 months now.

Quick backstory, I started with a 3 gallon betta tank for my youngest. This has gone somewhat well after starting out almost completely clueless. I've lost a snail along the way and almost certainly hastened our first betta's demise that happened this week from the tank getting up to 8 ppm ammonia early on. After the early issues I got a test kit, some Seachem Prime and that 3 gallon tank has been cycling for a couple weeks now. Mysterio 2 (the snail) and Bluefin 2 (the betta) seem to be doing well and my son hasn't figured out that they are replacements for the originals.

To the 20 gallon tank. Shortly after getting the betta tank it became apparent my son wasn't going to be satisfied with only being able to have one fish. So we got the Aqueon 20 gallon kit, filled it up, added the bottled stuff that came with it that was supposed to make the tank ready in 1-2 days. We added 4 neon tetra later that weekend who all promptly died within 2-3 hours. It was at that point that I dug into the research, got the test kit ordered that allowed me to save the small tank, and decided to get the 20 gallon tank cycled before adding any more fish.

I added ammonia up to 2 ppm and waited. After about 4 weeks of nothing I read some more and took the top off the tank thinking it needed more surface area exposed to help get it started. After another 4 weeks of nothing I changed out the filter cartridge in the small tank and moved it into the filter case of the big tank. This was after the small tank appeared cycle so I assumed the filter would be loaded up with bacteria that would kick start the process in the big tank. It's been about another 2 weeks since then I am still seeing no movement. The ammonia looks like it may have dropped some, but I'm chalking that up more to probably dilution from adding top off water since I've got no sign of nitrites or nitrates.

Anything else I may be missing? When I'm doing water changes on the small tank I make up some extra that is dosed with Prime to add to the large tank as well to top it off. I'm not sure what else would be preventing the bacteria from taking hold. It's a 6 year old boy's room so not exactly a hospital environment.

 

[Aiken Drum]

There is a lot of information there. Can you clarify a few things.
- You have a 3g tank with a betta and a snail? Everything is going OK there?
- You have a 20g that you set up, put some "stuff" in, stocked with 4 neons, and they died?
- You then started a fishless cycle in the 20g which isn't going well?
- You are taking water from the 3g when you do water changes and putting it into the 20g to transfer beneficial bacteria from the 3g to the 20g?

 

[LeoSpaceman]

Sorry, yes that intro got long.

Yes, 3 gal tank with a betta and snail are good. Tank is cycling.
Yes, 20 gal tank with the bottle of starter stuff from the kit. Fish died quickly.
Yes, fishless cycle in 20 gal tank is not going well.
No, I'm not taking water from the 3 gal tank and putting in the 20 gal. When I do a water change on the 3 gal (i.e. 1 gal), I'll prepare more like 1.5 gal of water that I dose with Prime. Add water from that bucket to top off both tanks. I did transfer the filter from the 3 gal cycled tank to the 20 gal tank about 2 weeks ago in an effort to transfer the bacteria.

There is a lot of information there. Can you clarify a few things.
- You have a 3g tank with a betta and a snail? Everything is going OK there?
- You have a 20g that you set up, put some "stuff" in, stocked with 4 neons, and they died?
- You then started a fishless cycle in the 20g which isn't going well?
- You are taking water from the 3g when you do water changes and putting it into the 20g to transfer beneficial bacteria from the 3g to the 20g?

 

[Aiken Drum]

No need to apologise. I just dont want to get into something i dont need to (and ive just got home from the pub and my brain isnt functioning so good, but dont tell anyone).

- Just for everyones peace of mind would you mind giving your water parameters on the 3g. 3g is a very small volume of water, and therefore very difficult to maintain good water parameters. If your are doing good there, very good job.

- The starter stuff is likely biological booster, ie beneficial bacteria in a bottle. Absolutely not your fault, but ive never heard from an aquarium hobbyist saying it 100% does what it claims on the bottle. At the very best it might speed up your cycle from months to weeks. At worst it does nothing. If not stored and transported in temperature conditions the bacteria will die off and have no effect.

- This is the fishless cycle guide people are usually guided to on this forum. Have a read through.

https://www.aquariumadvice.com/tips-and-tricks-for-your-fastest-fishless-cycle/

I dont agree with everything in there, but you will rarely get 2 aquarium hobbyists to agree on anything. My advice would be to dose ammonia to 4ppm, dose with biological booster (eg "stuff" or Dr Tims One and Only or Seachem Stability) or some established filter media. Test daily for ammonia, nitrite and nitrate. Every time ammonia drops below 1ppm then redose back up to 2ppm. When you are 0ppm ammonia and nitrite after 24h, and your nitrates are rising, your tank is cycled and you can do a big water change to get nitrates down and then add fish. We can discuss in more detail if you want.

- I dont understand your last point. Your filter from the 3g is now in the 20g? Then what is filtering your 3g? Is the betta and snail now in your 20g? Or did you just transfer the filter for a short period and it is now back on the 3g?

 

[LeoSpaceman]

Not sure if I've got all the relevant parameters you're looking for. pH is holding between 8.0-8.2. Just tested out of the tap and it's 8.4 which kind of surprised me. I don't have the hardness testing gear but my area of the country tends toward harder water. I could dig an estimate out of my brewing software probably if it's an important factor.

Ammonia and nitrites have been pegged at 0 for the last 2 weeks or so. Nitrates look to be under 10 ppm currently. I just did a water change a few days ago.

Looks like the starter "stuff" was nothing more than water conditioner. It doesn't say anything about bacteria.

As for the filter, the 3g tank is one of those Tetra half moons with a small Whisper filter on it. I took the cartridge out of there and put a new one in. I actually let the old one sit in the 3g tank for about a week thinking that would let bacteria migrate from there into the new filter so that I wouldn't take all the bacteria out. Not sure how necessary that was. After a week, I took the old filter out of the 3g tank and put it in the opening of the 20g filter box behind the larger filter cartridge that's already in there.

Checked everything out again tonight and no real change so I dosed the 20g tank up to 4 ppm ammonia. Is it plausible that if it was hanging between 1-2 ppm that wouldn't be enough to kick off a cycle?

 

[Aiken Drum]

So, you put an old filter cartridge from your 3g into the filter for your 20g to seed it with beneficial bacteria. Thats ok, it should help start things off.

4ppm ammonia will give the cycle a good dose of fuel to start it off. The lower amount you previouly put in won't have starved the cycle, it would just have slowed it down a little.

What is your tank temperature? Optimum temperature is 28c / 82.5f for growing beneficial bacteria.

I would consider a biological booster product. As previously said they are hit and miss, but won't do any harm.

Your pH is very high. It shouldnt affect the cycle but might cause issues with fish you put in there. I wouldnt normally advise to go chasing specific pH numbers, but i would consider putting a nice piece of driftwood in to bring it down, make sure you do a good drip acclimatisation of any new fish and keep an eye on any fish for signs of distress and look at other means of lowering the pH if needed. The high pH is likely the cause of your tetra deaths. It was a very quick result, and pH shock would explain it. Neons are low pH fish, and if they are moving from a lower pH setup into your high pH set up with no acclimatisation that is likely what killed them.

Also, be aware that fishless cycle can take anything between 2 weeks and several months. So patience is key, but 3 months with no movement is a long time. Have you considered starting over and doing a fish in cycle?

 

[LeoSpaceman]

The tank is at 78f. It came with a heater with a preset that I can't alter, so no real way to raise the temp unless I get a different heater.

I wondered about the pH, but then the more I read the consensus seemed to be to not worry about messing with pH. I certainly don't want to be running acid/base chemistry every time I mess with the water, but if it's as simple as putting some wood in I like that idea. Maybe a stupid question but when you say a piece of driftwood I'm assuming this is something I'd get at a store rather than just throwing any old stick from my yard in there?

I've come close a few times to just going fish in to get things started. I guess I'm glad I didn't since it probably would've been another round of ritual sacrifice with the pH situation. But certainly staring at an empty tank for 3 months has not exactly gotten anyone in my family excited about having it.

 

[LeoSpaceman]

Little follow up. I didn't go the driftwood route yet but had ordered some Indian Almond Leaves after reading in general they're good for bettas with the side effect of lowering pH for me.

Put a decent sized leaf in both my 3g and 20g tank on Saturday afternoon. Checked today and my pH is down to 7.4-7.6 Tops out the normal pH test kit, bottoms out the high pH test.

Which raises a question about pH shock and how much change is too much? I went from 8.0-8.2 to 7.4-7.6 in a matter of a little more than a day. No one seems worse for wear other than the tank water looking a little yellow (which I knew would happen from the leaf). Although I'm worried now every time I'm doing a water change I'm going to be hitting them with a pH shift. Did about a 25% change today and it tested more like 7.8 after that.

Anything to be concerned about?

And maybe wishful thinking but the ammonia test in the 20g tank seemed a little lighter green today. We'll see how that goes.