How do you tell if freshwater fishes have parasite ?

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Fish Herder
Fish of the Month!
May 30, 2021
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If you post some pictures of the fish it might offer more information.
If i can get a picture of the zebra or clown I will post; The clown hasn't lost weight it just hasn't grown any larger unlike the other 6 i purchased around the same time which have more than double in size and the red around the gills is quite extensive but no worse than the day i purchased. The one zebra is skinny but if it had worms would not all the other fishes have worms by now and would not more than one fish be impacted? Taking pictures is not easy because the aquairum is very heavily planted and the loaches are very shy and if they see any movement will retreat to their cave network. The one zebra is extremely thin and his spines are showing but he has other indication of age - my question is what would confirmation it is worms and not age ? Is it harmful to the fishes to just proactively treat for worms ?

Fish dying a short time after new fish are added to that tank usually die from an external bacterial or protozoan infection. New fish should always be quarantined for at least 2 (preferably 4) weeks before being added to an established tank to stop the introduction of diseases into the established tank.
Yes i know this - but i live in a condo and bylaws prohibit my setting up more aquariums. Also the carriers (at least with the barbs) were not effected - they are still alive today. I suppose i could do the 'sucker' route where i take a fish from my aquarium and put it in the qt tank after 4 weeks to see if it has a problem.
It's preferable not to mix several species of dwarf cichlid in the same tank because they are territorial and quite often fight. Even if they don't rip each other apart like bigger cichlids do, they still stress each other out and that weakens their immune system and makes them more vulnerable to diseases and death.
I know quite a bit about this topic; the nannacara is a single as is the female nijjesni; their aquarium has not have an issue and they don't fight - they do have their own hang out spots - the nannacara in the back and the nijjensi under a crypt leave near the front. If i had male nijjensi in there the story might be different as they would establish a territory (i've not seen the male nannacara become territorial though a female will be). What you said is general good information but it comes down to specific species and if you have pairs. The nijjensi area of territory can be quite large and they will double team other fishes once htey have established one but as i noted the single female is less of an issue in this regards and she has been quite passive. Also this aquarium has a school of 20 pygmy which they leave alone as well as 12 orange laser; you shouldn't keep cory with pairs of dwarf cichild for similar reason.
If you have lots of fish in a tank, even babies, you need to do lots of big water changes and gravel clean the substrate. Fish like suckermouth catfish (bristlenose) produce huge amounts of waste that can encourage protozoan parasites to explode in population, and lack of big water changes and gravel cleaning can let the pathogens get out of control and start killing fish. Your fish might not have an external protozoan infection but if you are keeping lots of fish in a ank, you need to do big (75%) water changes and gravel clean the substrate at least several times a week. The filter should also be cleaned at least once a month. this helps to minimise the number of disease organisms in the water and reduces the chance of the fish getting sick and dying.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.
Yea - the 120 has a lot of L204 but i do 50% water changes on all my aquairums once a week; the 120 gets 50% + 25% (two different water changes); during hte summer when the water warms up it will get 2 50% - but 'summer' will only be a few weeks before i move.

The following should be done if you ever lose a fish or the fish get sick.

Test the water for ammonia, nitrite, nitrate and pH.
I do this periodically; these tanks have been setup for years and are well cycled - i do weekly water changes - i have a ph probe in one of the tanks to monitor ph - nitrate is the only real issue that needs watching. The TDS (which you did not mention) has been creeping up despite large water changes and that does concern me. All these tanks have redudant filtertation with extra sponge filters. The 120 has 2 large sponge filters and 2 canister filters; the small aquariums have matten filters + sponge filters. The 120 is simply over populated. The 40b with all the pleco babies - that is a massively dense planted aquarium of extremely thickness (in plants); which is why i haven't been able to fish the plecos out. The 120 is a real concern because of the over population; i was suppose to move 6 months ago but delays in setting up the new places caused fishes to get larger than expected. I can state with 100% confidence that the angels and festum poop is not white (they are in the aquarium with the loaches); but i never actually seen a loach poop. The zebra I've seen are all quite fat 'cept for the one that has become skinny - i spent 20 minutes trying to get a picture and i can post some blurry ones but it won't sit still long enough for a good picture. I might be able to get the red gilled clown later - sometimes he sits still when i feed the fishes but today he keeps backing off when i try to photo him.

As for doing 75% water changes on the 120 every day - impossible. First the water is too cold and i don't have a hot hookup that will reach the room; 2nd it takes 3 to 4 hours to do a full water change on this aquarium and i don't have that kind of time right now (this suggestion works great on a small aquarium but it isn't feasible for a large one). The reason I'm asking the questions now is i'm trying to decide if i need to do some sort of pre-emptive treatment before i move but i can't identify a specific issue. The 29's do get 2 50% water changes a week during summer (1 during the winter - this has to do with the fact that i can only heat one 30 gallon pail over night and i want to do larger water changes on the 120).

When i created this thread my hope was to identify something more positive i could look for - i.e, if one fish has worms for 9 months then surely other fishes have worms but if no other fish has the skinnies then it is less likely to be worms - (that was a question not a statement); if i treat all my current tanks as 'qt' tanks prior to moving is there something that i can treat the fishes with that would be effective but not harm the fishes (not too hard on them). If i cut open one of the tetras would i be able to identify something or if it is clean does that mean the other fishes are clean - i have 16 serpae and smiliar number of cherry barbs in the 120 with the loaches and angels. I can post a picture of the 120 if that is helpful.

Wipe the inside of the glass down with a clean fish sponge. This removes the biofilm on the glass and the biofilm will contain lots of harmful bacteria, fungus, protozoans and various other microscopic life forms.

Do a 75% water change and gravel clean the substrate every day for a week or until the problem is identified. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use the media. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens so any medication (if needed) will work more effectively on the fish.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.

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