Newbie Who Needs Help With Cories And Ammonia

bobbme01

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Hey everyone.

After months of research, I started a 20gal tank (my first ever) about two months ago. Plan was for 5 cories 5 celestial pearl danios. After talking to some people, I decided to do fish-in cycle with Tetra Safe Start and two cories. Did weekly water changes, was initially using the filter that came with the tank but changed it after a couple of weeks because I wanted a higher gallon per hour turnover. Initially my readings were very high pH (I have a sand substrate- processing driftwood for this now to go in once ready), with low ammonia, low nitrites and high nitrates. I got what seemed to be a "bacterial bloom" and the tank became cloudy but this resolved, nitrites spiked minimally then went back to zero, but the ammonia never dropped to zero. I did get three more cories about the nitrites went back to zero.

The problem became with regard to feeding the cories. They don't eat right away, and all of the advice for feeding says 1- feed what they'll eat in 2 minutes then remove the rest, but also 2- that cories are scavengers and eat what's leftover off of the bottom. I read that you need pellets so I bought shrimp pellets but the cories just don't go after them right away. Out of fear for starving them because they don't eat anything in two minutes, I just left the food in there.

So naturally my ammonia levels have now shot up to 1ppm and I lost a fish. The other four look fine. I also now have a major algae problem (I'm only doing lights on for 12h off for 12h). Nitrites still at zero. I'm adding more of the safe start bacteria every time I change the water.

Any advance about managing the ammonia, my cories diets, and the algae are greatly appreciated! I don't want to lose more fish and want to do this right!
 

MrBryan723

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Water changes. Then more water changes. Cory cats aren't the best choice for a cycle. At least 25% a day at most 75% a day. You want to have around .25 to .5 ammonia for a fish in cycle. Much lower and it won't really cycle, any higher and it will harm your fish.
 

AZL

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Hey, i'm not years into the hobby either but this stuff I do have experience with. You did the right thing asking people but fish in cycle is never a good idea and as Mr Bryan has said corys are a little more delicate. I would suggest temporarily re-homing the fish while you do fish less cycle if feasible. If not there is a way to sort this out - I had a similar situation as my first tank was re-homed with me along with 6 corys and 3 plecs. The previous owners power washed the filter to remove algae killing the necessary bacteria forcing me to do a fish in cycle. Seachem Prime is a water conditioner that detoxifies ammonia and nitrite (the toxic stuff). You use a few drops to make tap water safe but a larger dose protects the fish from ammonia and nitrite. This needs to be done every 24 hours for all of the time these are reading over 0 on your water test. I found doing a 40% water change when ammonia and nitrite were first high, then a 25% one in a few days, then 25% to 30% weekly as things settled took enough of the toxins out to allow bacteria to catch up without shocking the fish or hindering the cycling. Tetra safe start isn't the best bacteria in a bottle - I like microbe-lift (Maidenhead Aquatics do it). The filter gel goes right on your media then the special blend in the water at the same time and weekly for a month or two. Test water and dose with prime daily until ammonia and nitrite are 0. when you see some nitrate the cycle is complete - one bacteria turns ammonia into nitrite, another nitrite into nitrate which is harmless unless extremely high. Nitrate is removed when you change water and through gas exchange on the water's surface. ensure your filter is powerful enough and that there is good surface movement. A couple of airstones as well will help the fish be more comfortable and help the bacteria colony develop. If you can move the fish out and cycle without them a bit of fish food will cycle the tank with the addition of bottled bacteria (microbe-lift or Seachem Stability) - my other tanks completed fishless cycle in a couple of weeks although I waited longer to add fish just to be sure. All the best
 

Dechi

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I feed my cory spirulina tabs. I break it into 1/4 part and put 1 or 2 pieces that fall on the bottom, at 9pm when the lights go off. In the morning, it’s all gone. You put it when it’s dark because Cories will come out at night and other fish won’t eat it.

I have 1 oto and 1 nerite shrimp that probably eat it as well, but if I only had the cory, I would probably feed him 1/4 tab per day. (My tank is about 70 days old now and I’m still waiting for it to be a little more mature before adding more cories and otos).

I’ve lost all my cories during my fish-in cycle, except this one. Cories aren’t good for fish-in cycles, they need good water parameters.

Do a WC everyday as long as you need to and hopefully you won’t lose anymore fish, but chances are you will.
 

GuppyDazzle

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You did the right thing asking people but fish in cycle is never a good idea and as Mr Bryan has said corys are a little more delicate. I would suggest temporarily re-homing the fish while you do fish less cycle if feasible.
I disagree. There's nothing wrong with fish-in cycling as long as you keep an eye on your test readings and do water changes to control the ammonia and nitrite levels. If you keep combined ammonia and nitrites at 1 ppm or below your fish will be fine, and there's enough ammonia to feed the cycle.

There's no need to panic and go rehome any fish so you can do this the "right" way. There are many different ways to accomplish what you want to do. For example, I have never used bottled bacteria. I won't list the many reasons why I don't, but with cycling the problem is the bottled bacteria will send your water readings wacky and you won't be able to see the cycle progress and do water changes to control it. There are many experienced fish keepers who swear by it and have had success.

You need to take in all the advice and decide what makes sense to you and what works for you.

I don't do water changes based on a schedule. I do water changes based on test readings. A schedule will emerge, but it will be a result of water changes and test readings. Why test at all if you're going to do 25% water changes on Mondays and Wednesdays?

When cycling without bottled bacteria, I would usually end up doing 30% water changes every other day, keeping ammonia and nitrite levels at 1 ppm or below. After about a month, with zero ammonia and zero nitrites, I'd test less often, eventually getting to testing once a month to make sure my water changes are enough to keep nitrate levels around 20 ppm.
 

Johnnybelfastboy

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30-40% wc daily will bring your ammonia levels down along with vacuming ur substrate as fish waste/food etc only adds to the ammonia/ nitrites. U say u were using the filter that came with it but then u changed it. Did u use the old medium from the old filter or use a new one? If you threw the old medium away u have prob thrown away all the beneficial bacteria from ur tank. Water changes r underestimated. Chemicals r overrated.... good luck anyway
 

jdhef

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Welcome to FishLore! I hope you find it helpful and enjoyable here
 
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AZL

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I agree that water changes are vital to ongoing maintenance and to resolving issues but find that daily ones, particularly if very larges %, shock the fish and don't allow things to settle. As for chemicals, again I agree that commercially produced chemical products are best avoided if there is a natural solution. For instance I wouldn't subject my fish to chemicals to clear algae when reducing light, reducing nutrients, and increasing live plants will address the issue. In an emergency situation like fish in cycle Prime is a good thing, absolutely not overrated as without it i wouldn't have been able to bring those corys and plecs re-homed with me with the bacteria culture in the filter destroyed though without losing some if not all and any survivors having neurological damage. It is the only commercially produced chemical I use apart from medications in my fresh and salt water tanks but it's also important to remember that being a chemical is not automatically bad - everything in the tank is a chemical apart from the fish, plants, and other organisms (and technically they along with all other matter are made up of chemical components). The water contains all of the chemicals involved in the nitrogen cycle as well as many others in trace and sometimes not so trace amounts. Essentially there are many perspectives in the hobby and very few people are 100% right or 100% wrong. You need to find point of consensus and what works for you for thing like water change amount and frequency, feeding, etc. In the case of fish in cycle however there is no gray area. Fish subjected to any level of ammonia and/or nitrite will die or have health issues down the line. Water changes will help but will not prevent this damage to the fish as they only reduce the levels. We are fortunate to have new innovation like Prime which converts ammonia to ammonium which is harmless to the fish but will still be consumed by the bacteria allowing the cycle to progress without harm coming to the fish.
 
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GuppyDazzle

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In the case of fish in cycle however there is no gray area. Fish subjected to any level of ammonia and/or nitrite will die or have health issues down the line. Water changes will help but will not prevent this damage to the fish as they only reduce the levels.
That's not true.

I've cycled 43 tanks over the past 10 years, all with fish in, and never had a fish death or sickness during the cycling process. As long as you keep combined ammonia and nitrites at 1 ppm or below the fish will be fine.

There is no one single "right" way to do things. Different fishkeepers often use different methods to maintain their tanks. Just because a particular method works for one person doesn't mean it's the only right way to do it.
 

Johnnybelfastboy

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That's not true.

I've cycled 43 tanks over the past 10 years, all with fish in, and never had a fish death or sickness during the cycling process. As long as you keep combined ammonia and nitrites at 1 ppm or below the fish will be fine.

There is no one single "right" way to do things. Different fishkeepers often use different methods to maintain their tanks. Just because a particular method works for one person doesn't mean it's the only right way to do it.
I agree we all have our own ways of doing things. If we post a problem we get many coflicting answers very rarely get a straight forward answer as things work better for some than others and in different ways. So we all need that little bit of pet detective in us to figure out what the problem is lol
 

AZL

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Very True

That's not true.

I've cycled 43 tanks over the past 10 years, all with fish in, and never had a fish death or sickness during the cycling process. As long as you keep combined ammonia and nitrites at 1 ppm or below the fish will be fine.

There is no one single "right" way to do things. Different fishkeepers often use different methods to maintain their tanks. Just because a particular method works for one person doesn't mean it's the only right way to do it.
I certainly agree that there is no single right or wrong way which was the majority of the gist of my post. Fish in cycle is another matter entirely however. It was done for years as hobbyists did not know that exposure to any level of ammonia and nitrite will cause permanent that may not be immediately apparent. You may not have had deaths or illness during those 43 fish in cycles but did a reasonable amount of the fish in each of those go on to live to their full lifespan?
 
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Momgoose56

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That's not true.

I've cycled 43 tanks over the past 10 years, all with fish in, and never had a fish death or sickness during the cycling process. As long as you keep combined ammonia and nitrites at 1 ppm or below the fish will be fine.

There is no one single "right" way to do things. Different fishkeepers often use different methods to maintain their tanks. Just because a particular method works for one person doesn't mean it's the only right way to do it.
From all I've read, Cory's are extremely sensitive to water conditions, ammonia and nitrites in particular:
"Cory Cats are also especially sensitive to ammonia, nitrite, and nitrate. The first two are the most important – ammonia and nitrite can kill in no time. This should go without saying, but make sure your tank is properly cycled before introducing any fish to your tank, let alone Corydoras."
Cory Catfish (Corydoras): The Complete Care, Breeding, & Info Guide
"Keep the levels of nitrites and ammonia at 0"
How to Care for Corydoras
"Pristine water quality is essential to good health in these catfish. They should never be added to new aquariums or those that have been neglected."
Corydoras Catfish Care Sheet
 

GuppyDazzle

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I certainly agree that there is no single right or wrong way which was the majority of the gist of my post. Fish in cycle is another matter entirely however. It was done for years as hobbyists did not know that exposure to any level of ammonia and nitrite will cause permanent that may not be immediately apparent. You may not have had deaths or illness during those 43 fish in cycles but did a reasonable amount of the fish in each of those go on to live to their full lifespan?
Yes.

What is your experience? Have you done fish-in cycles and had fish suffer ill effects? I'm just curious what you base your 100% certainty on.
 

Johnnybelfastboy

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From all I've read, Cory's are extremely sensitive to water conditions, ammonia and nitrites in particular:
"Cory Cats are also especially sensitive to ammonia, nitrite, and nitrate. The first two are the most important – ammonia and nitrite can kill in no time. This should go without saying, but make sure your tank is properly cycled before introducing any fish to your tank, let alone Corydoras."
Cory Catfish (Corydoras): The Complete Care, Breeding, & Info Guide
"Keep the levels of nitrites and ammonia at 0"
How to Care for Corydoras
"Pristine water quality is essential to good health in these catfish. They should never be added to new aquariums or those that have been neglected."
Corydoras Catfish Care Sheet
I hate cycling with fish.... they're terrible road users!
 

RockinRy

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I don’t think anyone helped you with your algae issue unless I missed it. If you don’t have any live plants you could just turn off your lights for a few days and do a blackout. That is effective against several types of algae and is really non-invasive.

Also, 12 hours on is actually quite a bit and might be part of your problem. I leave mine on for a long time too, but what I do is three hours on in the morning and then I have a siesta for several hours then I do a long period in the afternoon into night. Supposedly the break helps with algae, not sure on the science behind it though. Something to try I guess. I like it because I can look at it before work and after work and the lights are off when I’m gone.
 

AZL

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Yes.

What is your experience? Have you done fish-in cycles and had fish suffer ill effects? I'm just curious what you base your 100% certainty on.
I've worked with fish and other animals for well over 20 years. Before I moved to the UK I was a veterinary nurse and did rescue work with wild and domestic animals while studying biology before moving on to psychology which is my current profession (as well as part time work at my LFS). I had a long gap between keeping fish as a young person and the tanks I have now but am currently running a freshwater tropical community that was re-homed with me 6 months ago, a marine FOWLR tank for green spotted puffers for 5 months, and a reef tank which I hand built and is now 3 months in. I don't purport to be an expert in anything let alone fish keeping but I do understand the science behind maintaining a contained aquatic environment and there is no doubt after many rigorous studies conducted over the last decade or so that fish in cycling negatively impacts the health and life span of the fish that endure it. Looking back to fish my family and I kept years ago before the average hobbyist properly understood the nitrogen cycle and the subtle effects that variables in the aquarium have on the fish I can identify that every fish in situ for cycling developed health problems going forward and lived a much shorter than expected life span. The idea in fish in cycling is 'starter' fish that are 'expendable'. I don't see any fish as expendable and even if there were less evidence that fish in cycling negatively impacts the fish involved I can't see the point of subjecting living things to a potentially damaging environment when this can be avoided with a little patience.
 

Kjeldsen

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As long as you keep combined ammonia and nitrites at 1 ppm or below the fish will be fine.
Hmm not necessarily. Species, pH, temperature, are all factors in play. At the very least it's stressful for fish, and 1 ppm is generally considered 'lethal' by vets. Frogs die in agony in cycling tanks every day because people hear that it's fine, but even low ammonia levels go right through their skin.
 
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AZL

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I'm very careful about ammonia and nitrites with all of my fish but even more so as I have many scaleless or partially scaled fish - loaches in my freshwater tank, a pair of green spotted puffers in a species only marine tank, and am getting a goby soon for the reef tank. that also has anemones which are sensitive. I don't like any of them being subjected to it though, my marine tanks were fish less cycled and have been stable but while the freshwater tank was settling as it was re-homed with me with a crashed cycle I used Prime. I don't believe the corys and plecs that came in the tank would have survived fish in cycling and if they had they would almost certainly have developed health problems.
 
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