Need Help! And some advice. I think I broke my cycle.

[Ztoom]

Greetings!  I have a 75 gallon planted fresh water tank, that started out in a 53 gallon tank.  While it was in the 53 gallon tank (which ran for about 2 months), the aquarium appeared to cycle just fine.  While in the 53 tank the nitrite levels were 0.00 ppm, Ammonia 0.00, Nitrates would run around 5 to 10 ppm.  I did a fish in cycle method, with 6 Prestila tetras, some shrimp and 1 Cory.  When the tank cycled and was still reading zero on ammonia and nitrites, I added 6 bleeding heart tetras and 1 additional Cory, the tank was still running fine.  During this initial setup, I was doing 30 % daily water changes, sometimes maybe skipping a day.  My wife and I decided to move everything to a larger tank (now the 75 gallon) we moved all the substrate ( made up of bags of aqua soil, aquarium gravel and then a layer of sand on top) and added an additional bag of aquarium sand on top for the additional space of the 75.  We then moved all plants and fishj, shrimp etc to new tank and then topped off the tank with additional treated water to make up the difference.  I assume I have crashed my cycle since now, I originally had some ammonia showing up around .25 to .50 ppm, and nitrites were running around .25ppm, and nitrates around 5.0ppm.  I have been doing daily water changes and adding stability to aid in bacteria growth.  I now show 0 on ammonia, Nitrites are are creeping up to around .50 to 1.0 ppm and nitrates are around 5.0ppm to 10ppm. The nitrites never seem to go down even after water change, which I have been doing 30 to 40 % water change daily because I was scared of the nitrite levels.  My tap water does not register any nitrites when I test it.  Any help would be greatly appreciated.  I am just wondering if the tank just needs to cycle again?  I feed pretty light (once a day) and only enough for the fish to consume during the feeding.  Plants seem to be doing fine and have bounced back since the move.  Let me know if you need more info.  Oh!  My ph has always been around 7.2 to 7.6 throughout the entire time, with the exception of at very first the ph dropped to around 6.8 to 7.0 during the brief ammonia spike after the move.  Current readings as of this morning, after a 30% water change last night.  The pH is 7.2 to 7.6 range, ammonia 0 ppm, nitrite .50 ppm to 1.0 ppm (seems to be creeping up), Nitrate 5.0 to 10ppm.  I should mention that originally I was running a Tidal 75 on the 53 gallon tank, then moved it to the 75 gallon tank and added a new Fluval 407 to the 75 gallon tank.  All original bio media was moved and placed in the Fluval 407.

Edited March 15, 2022 by Ztoom
Missed some info

[SunniSki]

I actually did almost the same move as you but... I didn't move gravel.  I moved everything from a 45 to 75gallon.  I ended up dealing with fluctuations in nitrites for about 8 weeks I believe.  I don't have a miracle fix but I did daily water changes to reduce the toxicity of the nitrites... which was maybe about 20 gallons a day.  It seems like it took ages to cycle again and be "normal."

[gardenman]

I would say you more disrupted the cycle than broke the cycle. Things should settle down again pretty quickly for you. You've got a relatively small bioload (12 tetras, 2 cory cats, and some shrimp) for a 75-gallon tank. You might want to slow down on the water changes and just rely on how the fish are acting more than test results. (Tests aren't always as accurate as we'd like to think.) If the fish are acting fine, eating, behaving normally, I'd be inclined to assume everything was fine despite the test results. People can go a little crazy chasing perfect parameters and cause more trouble than they fix. If you're changing 30-40% each day and it's having no impact on the readings, I'd be more inclined to question the readings. 

[Ztoom]

Thanks for the info.  I guess I should have said, after the water change the nitrites briefly go down but are back up by the next morning.  Perhaps I will put off a water change for a day and see what happens.  the fish seem to be acting normally.  they eat and are not hanging out at top of tank or gasping by any means.  I was just concerned about the nitrite rise.  Before I did this, when I would test the nitrites were always at zero as well as ammonia.  Will 1ppm of nitrite be harmful if that is a true reading?

[KaitieG]

So, I know this is controversial, but I think for fairly low nitrite readings when you're trying to reestablish a cycle, a product like Prime can really be beneficial.  It claims to "detoxify" ammonia and nitrites, but it doesn't remove them, so your bacteria keep eating.  Some people disagree on whether or not this "detoxification" is possible, but I've had good success with it in combination with water changes.  I use it when I see any nitirite/ammonia readings because I have high Ph (which makes ammonia more toxic). 

The way I look at it is that things have already been disrupted from the moving around and are trying to recover.  Water changes tend to move stuff around and create a certain amount of disruption too.  So, if I can even extend them to every other day or so and if Prime can help keep the fish safe and if things don't go totally out of control, I'm giving everything a more stable environment to recover in by reducing the number of water changes (disruptions) as the tank establishes itself.  Totally unscientific, just my personal thought process and experience in seeing that water changes tend to make cycles take longer.

If this were me (and others likely have other plans of action that they'd take!), here's what I would do:

• Make sure I'm not cleaning filters/glass/decorations, etc to try to leave things as stable as possible for bacteria to get a foothold
• Dose with FritZyme 7 or something similar to try to get a jumpstart
• Dose with Prime every 24 hours
• If ammonia or nitrites climb above about 1 ppm each, do a partial water change but be really careful when I'm adding the water so that I move around gravel/plants/etc as little as possible
• Feed very sparingly (maybe even just every other day or so)
• If I had another tank, or a friend with a healthy tank, I'd squeeze the nasty filter water out into my new tank and leave a sponge or some media near my new filter (I've had good luck instant cycling with this method).