How do I fix my 30 gallon tank? Fish keep slowly dying.

The guppy with the curved body is skinny and could have intestinal worms and gill flukes. Most common livebearers from Asian fish farms have these parasites and the fish usually die before anyone works out what is going on. If you want to treat them for worms and gill flukes, section 3 of the following link has info about it.

If you have sulpha in the well water, that could be a bad sign. You really need to get the well water tested to find out if it's safe for people and fish.

If it does have sulpha in, it needs to be aerated for at least 24 hours before it's used in an aquarium. Filtering it with carbon would probably help too. You can put a plastic box filter in a container of well water. Have the box filter full of activated carbon and let it run for a couple of days to clean up the water. The box filter is attached to an air pump by airline. The air pump sits outside the tank or water container.
I have treated the tank twice with prazi pro as I thought it was parasites as well as two treatments of metro plex. As for the sulfur it is possible although I would have to say sulfur is a acid and thus I would think that my water would not be basic if the sulfur was in high levels.
 
Yes...

But in the light of some king of stressful environment, like sulfur in the water, the weakened fish could get overwhelmed much faster.

btw do you know the exact level there is ? Normally if you can smell it, it's already too much.
 
I have treated the tank twice with prazi pro as I thought it was parasites as well as two treatments of metro plex. As for the sulfur it is possible although I would have to say sulfur is a acid and thus I would think that my water would not be basic if the sulfur was in high levels.
Prazi-Pro contains praziquantel, which treats tape/ flat worms and gill flukes. Most ornamental aquarium fish have round/ thread worms and Levamisole is used to treat that. Flubendazole can also be used and treats both flat and round worms.

Getting the well water tested is the first point of call to make sure it's safe to use.
 
Yes...

But in the light of some king of stressful environment, like sulfur in the water, the weakened fish could get overwhelmed much faster.

btw do you know the exact level there is ? Normally if you can smell it, it's already too much.
I can not smell it but my friends can which is probably because they have not grown up around it
 
I would have to say sulfur is a acid and thus I would think that my water would not be basic if the sulfur was in high levels.
Sulfur is not an acid, it is an element. It can form compounds with other elements which are acids (like sulfuric acid), but not all sulfur compounds are acidic. The most common reason for sulfur in well water is due to bacteria which live in groundwater and produce a gas called hydrogen sulfide. It is a gas and smells like rotten eggs. It can act as a weak acid if it dissolves in water, but groundwater usually also has a lot of dissolved minerals which would be more than enough to neutralize that small amount of acid and overpower it, which is why your water is basic.

I can not smell it but my friends can which is probably because they have not grown up around it
Just because you can't smell something, doesn't mean it's not there. You're correct, you've probably been "nose-blind" to the hydrogen sulfide smell for a long time. The fact that it is noticeable to your friends suggests that there are high enough amounts of hydrogen sulfide to be meaningful for fish health. I agree with the others, if there's hydrogen sulfide in the water, that is probably causing a lot of your issues.

I would suggest looking into some sort of filter for your water—something with activated carbon. You could add carbon to your existing tank filter, get one of those filters that attach to your sink faucet, or even run water through a Brita filter (or similar) before your water change. You might be able to solve a lot of your problems with this simple change, so give it a try before continuing to throw medications at the issue.
 
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I set up my dads 40 something year old 30 gallon fish tank back in December of 2023. All of the gravel and rocks were also my fathers and were sanitized using boiling water before placed in the tank. The tank only ran for about 2 weeks before I got fish a beginners mistake I was way to excited, and realize that this was a grave mistake, but never the less I started with 4 swords, 2 platies, and two guppies. I also had bought one live plant which had brought two stowaways, snails, which at the time I did not realize how much of a pest they would become. Within 2 weeks everything was still going well and we bought a Chinese algae eater and a common pleco. About a week later the big male platy died and all of the fish were constantly hiding turns out it was the chinese algae eater and we had to return him. Within a couple days my pleco died, we believed that he starved to death. When we brought the dead pleco in we bought almost 8 guppies (probably the biggest mistake I had ever made. Little did I know that the fish store we bought our fish from had columinaris and within a month all of my fish were dead other than the 5 babies that had been had my some of the guppies and the 2 platies and 3 swords and one adult guppy named Aunty blue tail. the columinaris I stopped with hydrogen peroxide over a period of a month. Weeks later I bought a little female micky platy from petsmart, to test if the columinaris was gone and a week after that my friend bought me 4 danios for my birthday. A week after that I got 3 baby blue wag platys. And a week after that the micky platy wasted away and died, then my female platy did, then my male platy did, then I got a endler and 3 neocardinias (shrimp) to deal witht the hair algae problem. Then one of the swords wasted away and died and then another did and a third did, then the two female baby platies died and all three shrimp died.( note at this point there are 40 or more snails and lots of algae). At this point I thought that the snails were the problem and that crushing them and feeding them to my fish was not working, so I stopped doing that and I got a chain loach and he cleaned up most of the snails and I got my dream fish which I was debating because I knew that fish were dying but my dad trying to not have me freak out just said fish die and none had died in about 2 weeks. So I got a hillstream loach. Except I have a under gravel filter and the snails reproduce under the panels and come up through the up pipes so they re populated and one of my baby guppies wasted away and died, and now I treated the tank with prazi pro and the next day my fat danio had a bunch of hoels in it and was dead, then death stopped for a week and then Aunty blue tail got it and has been wasting away, and that is were we are at. I am infested with snails, Aunty blue tail has a bent tail and has fin rot on her tail and is emaciated jusst like all of the other ones who have died before her, and just like them eventually I will find her breathing really hard on the bottom of the tank and then dead. And at this point the thought is that the ethical choice is to give all of my fish to the one store I trust because they actually are good with fish and are proffesionals/experts not just people hired for $15 an hour. They raise the fish and so on. I just do not know what to do anymore.
As we all learn the hard way, quarantine new fish and pretreat to catch diseases before we put them in our disease-free tanks. This is a good article you might find helpful!
 
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You need a filter that contains impregnated and non-impregnated high H2S capacity carbons, that can handle high hydrogen sulfide concentrations. High pH and alkalinity also influence the effectiveness of the carbon.
 
So I went to my local fish shop and talked to a guy who is actually going to college for Ichthyology and he asked me questions and tested my water. All of my water parameters were good. I also mentioned the sulfur so of the remaining water from my tank that I had brought we capped it of and waited and then we opened it up and smelled there is no sulfur smell. He said that it was likely because I have soft water, that because of that I should probably stick to tetras, loches, etc. I am going to take his advice and see what happens, thank you all so much for your advice it truly was helpful, I really do want this to work out , thank you so much.
 
What did you get the water tested for and what were the results in numbers?
 
What did you get the water tested for and what were the results in numbers?
It got tested for ammonia, nitrates, nitrites, pH, GH and KH
I do not know the numbers for ammonia, nitrates, nitrites other than they were perfectly normal, the pH was 7.4, the KH was really high at 9 and the GH was 2-3. So basically my pH will not change a lot because my kH is so high and I have really really really soft water because the GH was so low.
 
Having a KH of 9dGH isn't that high (160ppm) but it definitely stops the pH dropping (as you mentioned).

Having a GH of 2-3dGH is really low (36-54ppm), which is upper Amazon River hardness, the sort of place a lot of tetras and Corydoras come from. Definitely too soft for common livebearers from Asian fish farms.

Because there has been issues with this tank, I would start out with a group of cheap tetras and see how they do over a month or two before adding anything else. If it is just the soft water they should be fine, but if they die, then there's still a problem.
 
That was the plan that I made with the fish guy at the private fish store I now go to after the severe disease issues from my local petsmart. I will be bringing in my remaining live bearers so they do not die just because of the water parameters, and then we are going to just try ¨soft¨ water fish like tetras, my loaches will be staying because I have never had a problem keeping loaches in fact I had a really weak loach get better in my tank. I do not like the white skirt tetras but the cardinals are not bad. But knowing that loaches do well in my tank I am not opposed to just having a couple of them, sure it will be roomy, but I do not need dozens of fish. I will see, it depends I have never been one for schooling fish and I live the corydoras but the problem is I can only have so many foraging fish. I have three massive aqarium books so I should be able to determine what ones are soft water and which are not, from there its just trial and error I guess. I am just not used to this with animals, I have grown up on a dairy farm where most of the cattle live for years and it is rare to see one die, so I am new to witnessing so many animals die.
If youn have any more advice I am all ears, I love learning about fish, and above all I love learning from other people especially from their mistakes so that I do not have to make them.
 
That was the plan that I made with the fish guy at the private fish store I now go to after the severe disease issues from my local petsmart. I
I once bought a fish from PetSmart, and it died within a week and also wiped out all the other fish in the tank just as fast. In my case, it wasn't the water parameters but an aggressive strain of columnaris, courtesy of PetSmart. I had to break down and disinfect the whole tank. That was the last time I bought fish from big box stores.

When in doubt about a supplier, always quarantine the fish first. I wish I did. There is only one LFS near me that quarantines and treats their fish before selling to customers.
 
I should be able to determine what ones are soft water and which are not, from there its just trial and error I guess.
If your books don't cover it, Seriouslyfish.com will give you the hardness ranges for each species. They also detail some specific information such as fast/slow flow, group size, decor... so you can see what is viable for your tank without guesswork.
 

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