Internal Parasite

[FranzAndrei]

Poor water quality comes from a lack of water changes, and undersized filtration, but even excessive filtration does not replace the need for water changes.
The bacteria that cause "some" internal problems, are ubiquitous, and become pathogenic when stress lowers the fishes immune system ask Kno4te said.
And although algae is not usually dangerous (depending on species, slime algae(Cyanobacteria can be)), it is sometimes an indication that not large enough, and frequent enough water changes are being done, because algae thrives on nutrients like nitrate.
If your tank is small, under 100 gallons, you need to do more water changes to keep the tank from becoming a fish toilet, the a larger tank, the longer it tanks to become polluted.
I test for nitrate, and if the tank water hits 10ppm, I consider it time to change 40%-50% of the water ( that may be considered excessive by some aquarists, I consider it minimal).
Another indicator of the need for water changes for me, is my tap water has a pH of around 7.8.
If after couple days, pH of the tank drops 7 or 6.9, that means to me its time for the same type water changes as above., because of acidification, brought on by, an excess nutrients.
These numbers may mean more than one water change per week, they may mean a water change every other day, or maybe not.
The bigger the fish gets, the more water changes it needs, often dependent on tank size.

wow thank you very much. you answered all my questions! thanks!!!

 

[duanes]

Doesn't your buffering capacity (KH) also protect your tank from a PH drop? With a KH of 8 degrees, it would take a lot of acidification to drop my PH from 7.8, and I would see an increase in nitrates (past 20ppm) long before this happens.

Yes alkalinity protects from acidification, a higher alkalinity may allow less water changes, as long as nitrate also stays level.
When I lived in Milwaukee my alkalinity averaged 100ppm, so it usually remained stable, but I still changed water when nitrates rose. The reason I used both parameters as water change indicators.

 

[Coryloach]

How can my flowerhorn acquire internal parasite? can someone tell me all the factors that a flowerhorn may acquire internal parasite. thanks so much guys

In wild caught fish, they are naturally found in the gut not causing many issues. In aquariums, due to the more stressful conditions, any sort of stress can trigger the parasites to spread to the fish's organs. If a parasite infection is confirmed via microscopic observation, they're best treated for via meds. No amount of clean water will eliminate them although it may slow the progression via increased immune system response, and thus also slow the spread to other fish, until the next stressor.

The presence of protozoa/worms, even in a low level infection when just in the gut, can decrease the fish's immune system and they become prone to secondary bacterial infections if water quality as suggested by Duanes is not maintained.

The problem is, that once the parasites spreads outside the gut, they're not that easily treated, even with correct medication. I am not one that would promote the irresponsible usage of medication but in the case of protozoa/worms, there's increased evidence to suggest that a prophylactic treatment may be beneficial, providing one knows exactly what they need to treat with, has researched the safest ways to do so, and is aware of any consequence of such medication.

In terms of how fish get it, apart that many naturally bring it in from the wild or contaminated tanks in fish shops, fish can also be infected via contaminated water, fish to fish transmission, fish eating other fish's feces, frozen and fresh food sources, etc....

Providing it is not coming from one's tap water, and proper bio-security measures are in place when introducing anything new to the tank, one can theoretically eliminate a lot of those pathogenic parasites from their tank for good.

Note, that I talk about parasites and not bacteria. The best way to prevent bacterial infections is best done via adequate water changes. The less water you change, the higher the bacterial load. Pathogenic bacteria is naturally occurring in the water and besides attacking fish with weak immune system, fish with open wounds, etc.., it can also attack healthy fish if the load of the pathogenic bacteria is high enough.