Finally got new mollies in cycled tank and i got questions

Mollyforever

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I’ve been doing a fishless cycle for about a month and a half and I finally got three new mollies in the 20gallon tank!

When I first put them in the tank ammonia was 0 the next day but I had nitrites fluctuating between 0.25 and 0.5. I did a big water change two days in a row and skipped a day and now the nitrites are at 0 and nitrate under 10!

Meanwhile, I have two mollies in my other 10 gallon tank that has been running for more than three months. They are healthy except for internal parasites. I have treated them with levamisole hcl abut my lfs saw the photos of their poop and said it was probably protozoan issues. Makes sense cuz I lost three mollies in the 10 gallon tank one by one over a week or two and the two left are the survivors. I have fed them food mixed with metroplex and focus for the past five days. They still expel stringy or clear poop. I do water changes everyday.

When can I add my two mollies in the new tank? Should I continue with the metroplex food?

The new mollies in the 20gallon tank are all females, and the two in the 10gallon tank are one female and one male. The female has been skinny since the day I got her. She looks happy but she is still skinny and would not get pregnant.
 

Byron

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I have twice used metronidazole for internal protozoan issues, so I have some info from the marine biologist I consulted then. Feed only metro-laced food for at least ten straight days, nothing else. This should deal with the issue, though I do not know the specific protozoan so I am only offering my experience when it did work. You might use it for 14 days to be safe. Metronidazole has no harmful side effects, though it is an antibiotic but once used it can be continued.

Edited to correct typo that Colin spotted...thanks C.
 
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Colin_T

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You might use it for 145 days to be safe.
pretty sure that is meant to be 14 days straight. gotta love typos :)

You should feed the medicated food 3 times a day too, to maximise its effectiveness. Make sure all the fish eat a lot of the medicated food each time they are fed.

-------------------
For the OP,

What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
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).

If the water is too saft (GH less than 200ppm), you will have problems with mollies. They do best in water with a GH above 250ppm and a pH above 7.0.

You can add some salt (sodium chloride) to the tank to help kill external protozoans, gill flukes and some other disease organisms. See below for directions with salt.

The following link has information about stringy white poop in fish. It might provide you with some more information.

-------------------
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 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

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 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt 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 (1-2 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.

If 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.

You can use salt while feeding the medicated food.
 
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Mollyforever

Mollyforever

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I have twice used metronidazole for internal protozoan issues, so I have some info from the marine biologist I consulted then. Feed only metro-laced food for at least ten straight days, nothing else. This should deal with the issue, though I do not know the specific protozoan so I am only offering my experience when it did work. You might use it for 145 days to be safe. Metronidazole has no harmful side effects, though it is an antibiotic but once used it can be continued.
Okay! I just made a fresh batch of metroplex laced food using freeze dried brine shrimp, some veggies and flake!
 
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Mollyforever

Mollyforever

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pretty sure that is meant to be 14 days straight. gotta love typos :)

You should feed the medicated food 3 times a day too, to maximise its effectiveness. Make sure all the fish eat a lot of the medicated food each time they are fed.

-------------------
For the OP,

What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
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).

If the water is too saft (GH less than 200ppm), you will have problems with mollies. They do best in water with a GH above 250ppm and a pH above 7.0.

You can add some salt (sodium chloride) to the tank to help kill external protozoans, gill flukes and some other disease organisms. See below for directions with salt.

The following link has information about stringy white poop in fish. It might provide you with some more information.

-------------------
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 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

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 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt 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 (1-2 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.

If 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.

You can use salt while feeding the medicated food.
My GH and KH is around 200 and pH is 7.8. I just use tap water treated with prime!

I tried salt before but my fish seem to be very uncomfortable when I use it and last time some mollies got bloated or sick after this and died.. Probably I didnt use it correctly although I followed directions. Though I will try if another 10 days of medicated food doesnt work!

Thank u so much for the thorough and helpful reply!
 

Ichthys

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If you’re using salt for Mollies you should use marine salt. It’s the other minerals in it that are beneficial to them, not the salt itself. They don’t always do well in just salt.
 

Byron

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GH at 200 ppm (= 11 dH) is a bit low for mollies, and while this is not too soft, over time this might be an issue. The marine salts would help here, as they contain the salts of calcium and magnesium as well as sodium chloride (common "salt"). These are OK to use as only the mollies are in the tank; soft water fish would not benefit from this, quite the opposite. And the GH is OK for most livebearers other than mollies (and I am not saying it is insufficient for mollies, just noting it is not all that high).
 
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Mollyforever

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If you’re using salt for Mollies you should use marine salt. It’s the other minerals in it that are beneficial to them, not the salt itself. They don’t always do well in just salt.
I used API aquarium salt. Is marine salt a different type of salt?😭
 
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Mollyforever

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