I can only keep livebearers alive in my tank

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huso

Aquarium Advice Newbie
Joined
Jun 23, 2024
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USA
Every value in my tank looks ok but for some reason, only livebearers can live like mollies and platys. Every fish I put has died in less than 12 hours while the 4 livebearers live great. I and people at the pet store can't seem to figure out why. Please help if you have any clue why this happens.
 
What are your complete water analysis values? pH, Ammonia, Nitrite, Nitrate, General Hardness, salinity ( or just Did you add salt to the water for the livebearers? ) What are the other fish you tried to put into the tank?
 
What are your complete water analysis values? pH, Ammonia, Nitrite, Nitrate, General Hardness, salinity ( or just Did you add salt to the water for the livebearers? ) What are the other fish you tried to put into the tank?
ammonia-0 nitrite-0 nitrate-0 ph-7.2 gh-30 kh-80 no salt I tried dwarf gourami, neon tetras, and glofish. I acclimated them for an hour. The current fish in the tank are 2 black mollies 2 platies.
 
ammonia-0 nitrite-0 nitrate-0 ph-7.2 gh-30 kh-80 no salt I tried dwarf gourami, neon tetras, and glofish. I acclimated them for an hour. The current fish in the tank are 2 black mollies 2 platies.
What size tank is this? How long has the tank been running? What are you using to have 0 nitrates? Describe your acclimation method please.
 
What size tank is this? How long has the tank been running? What are you using to have 0 nitrates? Describe your acclimation method please.
20 gal, around 2.5 weeks end of 1st week I added the first fish (still alive). I use a prime water conditioner and have live plants. I put the bag in water for 20 minutes, after that I open the bag and add some tank water, wait 10 minutes, and do it again. On the third water add I wait 20 minutes and add the fish.
 
20 gal, around 2.5 weeks end of 1st week I added the first fish (still alive). I use a prime water conditioner and have live plants. I put the bag in water for 20 minutes, after that I open the bag and add some tank water, wait 10 minutes, and do it again. On the third water add I wait 20 minutes and add the fish.
Are you familiar with the cycling process? Your tank is too new for it to be cycled unless you added filter material from an established tank or one of the " bacteria in a bottle" products. That is part of your problem.
It usually takes about a week from the time you add the first fish to start seeing ammonia in your water. That's the beginning of the nitrogen cycle. ( Read through this thread for more info: Fish In Cycle Guide. )

Regarding your acclimation method. you were fine until that last waiting 20 minutes to add the fish to the tank. When you bag acclimate the fish, the fish use up the oxygen in the water rather quickly. When you add water to the bag, you want to add enough that you are changing no more than 25% of the water volume in the bag. This process should be repeated at least 3-4 times. If necessary, remove some of the water from the bag so that it doesn't get overfilled and sink into the aquarium. Once the amount of water in the bag is at least 75% your water and 25% the water the fish came in, you can release the fish into the tank. This should be done by pouring the fish into a net over a container so that none of the water in the bag goes into the tank. ( The same applies if you need to remove water from the bag during acclimation. )
Regarding your fish selection, many Dwarf Gouramis carry a virus which makes them rather fragile fish when the original dwarf gouramis were a hardy specie. You would be wise to avoid any of the gouramis until you are more familiar with fish keeping protocols . Tetras ( the neons ) are not good first fish and would be better in more established tanks. Assuming the glofish were danios, they are good indicators of something in your water that is off and needs attention. If they were the Glo Tetras, same applies as the neons. There are many types of glo fish so I can't speak directly to all of the possibilities of them all. There is also the possibility that you bought poor or sickly fish without knowing it and they couldn't handle the acclimation.
There is another possibility: when you say the GH is 30, do you mean 30 PPM or do you mean 30 drops ( assuming you are using a liquid GH test kit?)
 
I used a strip and gh I ment general hardness. I did some research about the cycle and if some fish in the tank have been living in there for more than week and a half with some algea growing, shouldnt the cycle have started. Also glofish were tetras.
 
Are you familiar with the cycling process? Your tank is too new for it to be cycled unless you added filter material from an established tank or one of the " bacteria in a bottle" products. That is part of your problem.
It usually takes about a week from the time you add the first fish to start seeing ammonia in your water. That's the beginning of the nitrogen cycle. ( Read through this thread for more info: Fish In Cycle Guide. )

Regarding your acclimation method. you were fine until that last waiting 20 minutes to add the fish to the tank. When you bag acclimate the fish, the fish use up the oxygen in the water rather quickly. When you add water to the bag, you want to add enough that you are changing no more than 25% of the water volume in the bag. This process should be repeated at least 3-4 times. If necessary, remove some of the water from the bag so that it doesn't get overfilled and sink into the aquarium. Once the amount of water in the bag is at least 75% your water and 25% the water the fish came in, you can release the fish into the tank. This should be done by pouring the fish into a net over a container so that none of the water in the bag goes into the tank. ( The same applies if you need to remove water from the bag during acclimation. )
Regarding your fish selection, many Dwarf Gouramis carry a virus which makes them rather fragile fish when the original dwarf gouramis were a hardy specie. You would be wise to avoid any of the gouramis until you are more familiar with fish keeping protocols . Tetras ( the neons ) are not good first fish and would be better in more established tanks. Assuming the glofish were danios, they are good indicators of something in your water that is off and needs attention. If they were the Glo Tetras, same applies as the neons. There are many types of glo fish so I can't speak directly to all of the possibilities of them all. There is also the possibility that you bought poor or sickly fish without knowing it and they couldn't handle the acclimation.
There is another possibility: when you say the GH is 30, do you mean 30 PPM or do you mean 30 drops ( assuming you are using a liquid GH test kit?)
I used a strip and gh I ment general hardness. I did some research about the cycle and if some fish in the tank have been living in there for more than week and a half with some algea growing, shouldnt the cycle have started. Also glofish were tetras.
 
Okay, the GH should not be the other possibility.
Yes, the cycling process should have started with fish in the tank for over a week but that process takes time, usually at least 6 -8 weeks plus to complete. During the process, the ammonia and nitrite levels become toxic to the fish which means doing routine water changes to keep these levels at " acceptable" levels to keep the fish alive. This is going to be a long process of many months before your tank will be fully cycled and able to be fully stocked. Mollies and Platies are generally very hardy fish which is why they are commonly used to do " fish in " cycling. You will know when your cycling process has completed when you see 0 ammonia and 0 nitrites and a rising nitrate level. The nitrates are the end result of the cycling process. This is what it looks like in graph form: Nitrogen cycle.jpg


You'll notice that the beginning and the end of the cycling process looks exactly the same with the exception of the presence of nitrates at the end.
I know this hasn't really answered your question about why only the Molly and Platy survive but there is more information you need to know before adding other types of fish to your tank.
What the end of the cycling process means is that there are enough nitrifying microbes present to handle the ammonia load present at that time. That means that if you have 1 fish in the tank, at the end of the cycling process there are enough microbes for the amount of ammonia that 1 fish or similar fish produces. The same applies if you use 10 fish or 100 fish or more fish. Your tank will be cycled for the amount of fish present at the end of the cycle. It doesn't mean that if you used 1 fish to cycle the tank that at the end you can add 10 more and not face problems. The biological filter bed is actually a living " organism" that grows and shrinks to the amount of ammonia being produced. In your case, you could cycle your aquarium with just the existing fish you already have or add more of them to help build a larger microbe bed ( a.k.a. Biological filter). If you do want to add more fish, you need to do this before the ammonia level starts to rise. Products like PRIME or other similar products do not remove ammonia so they are not the answer for an uncycled tank. You would need to do water changes to dilute the amount of ammonia present. Once your ammonia level starts to rise, you are best off not adding any more fish until the whole process finishes. Patience is the key to a successful aquarium. ;)
Once your tank has cycled, we can discuss fish selection in more details. :)

Hope this helps. (y)
 
Okay, the GH should not be the other possibility.
Yes, the cycling process should have started with fish in the tank for over a week but that process takes time, usually at least 6 -8 weeks plus to complete. During the process, the ammonia and nitrite levels become toxic to the fish which means doing routine water changes to keep these levels at " acceptable" levels to keep the fish alive. This is going to be a long process of many months before your tank will be fully cycled and able to be fully stocked. Mollies and Platies are generally very hardy fish which is why they are commonly used to do " fish in " cycling. You will know when your cycling process has completed when you see 0 ammonia and 0 nitrites and a rising nitrate level. The nitrates are the end result of the cycling process. This is what it looks like in graph form: View attachment 390181


You'll notice that the beginning and the end of the cycling process looks exactly the same with the exception of the presence of nitrates at the end.
I know this hasn't really answered your question about why only the Molly and Platy survive but there is more information you need to know before adding other types of fish to your tank.
What the end of the cycling process means is that there are enough nitrifying microbes present to handle the ammonia load present at that time. That means that if you have 1 fish in the tank, at the end of the cycling process there are enough microbes for the amount of ammonia that 1 fish or similar fish produces. The same applies if you use 10 fish or 100 fish or more fish. Your tank will be cycled for the amount of fish present at the end of the cycle. It doesn't mean that if you used 1 fish to cycle the tank that at the end you can add 10 more and not face problems. The biological filter bed is actually a living " organism" that grows and shrinks to the amount of ammonia being produced. In your case, you could cycle your aquarium with just the existing fish you already have or add more of them to help build a larger microbe bed ( a.k.a. Biological filter). If you do want to add more fish, you need to do this before the ammonia level starts to rise. Products like PRIME or other similar products do not remove ammonia so they are not the answer for an uncycled tank. You would need to do water changes to dilute the amount of ammonia present. Once your ammonia level starts to rise, you are best off not adding any more fish until the whole process finishes. Patience is the key to a successful aquarium. ;)
Once your tank has cycled, we can discuss fish selection in more details. :)

Hope this helps. (y)
should i do weekly 25% water changes untill i see nitarate levels go up and nitrite and ammonia levels go down? I saw you said you can add more fish to help the process would zebra danios or a typr of danio would be good for that purpose?
 
In the beginning you need to check your ammonia and nitrite levels more frequently and do water changes if the combined value of the ammonia and nitrite exceeds 0.5 ppm so that may be more than once a week and more ( or less) than 25%. You will need to do some math here to see how much water needs to be changed to get that reading under 0.5. ( i.e if the level was 1.0, doing a 50% water change will only bring the level down to 0.5 so you need to do a larger amount of water or multiple water changes that day. ) Once your tank has cycled, a weekly water change should be done to help replenish minerals and keep the nitrate level below 40 ppm. How much water that needs to be is determined by the number of fish you have in the tank.

As for adding other fish, Danios are good fish and generally hardy but keep in mind that they are great " Canaries in the coal mine" because if the water gets bad, they die, quickly, and usually before other fish. They should be in schools of at least 5 or 6 so plan on that if you are going to add them. (y)
 
I am probably gonna buy 5 zebra danios and a master test kit tomorrow from the pet store, I am gonna buy the fish I want like tetras, etc after the cycle is complete. Thanks for the effort you put in to help me, I appreciate it.
 
I am probably gonna buy 5 zebra danios and a master test kit tomorrow from the pet store, I am gonna buy the fish I want like tetras, etc after the cycle is complete. Thanks for the effort you put in to help me, I appreciate it.
No problem. That's why we are here. (y)
Quick hint, the reagents in the kits have an expiration date stamped on them. Make sure you get the one with the furthest expiration date. Expired reagents will still give you results only they will be inaccurate.
 

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