New again to having fish

[bkrengel]

Hello, new here. I had fish growing up and I am just now getting back into it. I just started a new tank 12 days ago. I made the mistake of getting fish 3 days after starting the tank and sadly lost both Molly fish after 2 days. After losing the fish I did a 50% water change and added Tetra Easy balance and aquarium salt. I let the tank run for another week and just added new fish after testing the water at home and having the fish store test it as well. All perimeters are supposedly just right. After one day my black Molly is swimming around happily and eating well. My Creamsicle Molly is displaying what I think might be shimmying but I think he came from the store that way, and my gold panda Molly is spending quite a bit of time sitting on the bottom of the tank. He comes and swims around in little bits and eats well. Then goes back to the bottom. I just changed the water a week ago so I’m nervous to change any of it again yet. I’ve only been feeding once per day to start. Ammonia, nitrate, nitrite, chlorine all 0, ph 7.5, in CO we have hard water. Alkalinity a little on the high side. I added quick start back on the 14th, added stress coat today when I saw the panda displaying bottom of tank behavior. My Creamsicle also came with a weird kink in his tail from the store ( Wish I’d of noticed before I bought) so I’ve been contemplating removing him from the tank. Would really appreciate help in what to do. They’ve only been in the tank for less than 48 hours so I know it’s early. It’s a 10 gallon tank. Temp is at 78 degrees. I attached a picture of the tail concern.

 

[Colin_T]

Hi and welcome to the forum

You are doing a fish in cycle, which simply means you have fish in the tank while the filters develop the beneficial bacteria that keeps the ammonia and nitrite at 0ppm. It takes about 4-6 weeks for the cycle to complete.

Until then do a 75% water change and gravel clean the substrate any day you have an ammonia or nitrite reading above 0ppm. When the filter has cycled you can feed them more often and do a 75% water change and gravel clean once a week.

Big water changes will not affect the beneficial filter bacteria because they live on hard surfaces, not in the water. Harmful disease organisms live on the fish and in the water.

Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

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What is the GH (general hardness), KH (carbonate hardness) of your water supply in numbers?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

Mollies need a pH above 7.0 (your pH is fine at 7.5), and they need a GH of 250ppm or above.

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Livebearers get the shimmies (swimming in one spot and not really moving) if the GH or pH is too low, or they have an external protozoan infection like Costia, Chilodonella or Trichodina.

The yellow molly in the picture is really skinny and has flared gills. This is usually caused by gill flukes and or intestinal worms.

You can treat gill flukes and most external protozoan infections with salt. Intestinal worms will need a deworming medication. I would try salt first and see how the fish looks after a few weeks.

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SALT
You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 2 heaped tablespoon per 20 litres of water.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 4 heaped tablespoons per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate (4 heaped tablespoons per 20 litres) will affect some plants and some snails. The lower dose rate (2 heaped tablespoons per 20 litres) will not affect fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

When you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

 

[bkrengel]

Thank you so much for your help! I will keep a very close eye on the ammonia level and add aquarium salt to help the fish having issues. I appreciate all the advice on how to do the water changes too! I just checked the water today because my black Molly is hanging out by the top of my heater in the corner and my gold panda Molly is at the bottom of the heater sitting on the rocks. The other fish in tank is also a Molly that seems a little more aggressive. Water :
Ammonia 0
NO3: 0
NO2: 0
PH: 7.5
KH: 80
GH: 60
Temp was 77, just turned up to 78
Any ideas on why they are hanging out by the heater at top and bottom?

 

[Colin_T]

If the fish have gill flukes (the yellow one in the picture probably does), the gill flukes make it harder for the fish to breath so they hang out near the surface or by a filter outlet where the oxygen levels are higher. Salt should treat the gill flukes.

The fish sitting on the bottom might be stressed or getting picked on by another fish. Mollies have a pecking order with the biggest meanest fish at the top and they bully the weaker subordinate fish. If you have several male mollies, the dominant one might be picking on the weaker one.

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Your GH is too low for mollies and will need to be increased to 250ppm. You can do this with a Rift Lake water conditioner, available from most pet shops or online. The Rift Lake water conditioner containers minerals like calcium chloride, magnesium chloride and a few other things, which increase the GH.

You will need to make up water and add the Rift Lake conditioner before using it. It normally takes 24 hours for the minerals to dissolve completely and you need to get the GH to the correct level before using the water in the tank. And you need to do this every time you do a water change. It's not urgent yet, but it will need to be done in the near future if you want the fish to survive for any length of time. In the mean time, salt should help.