What causes illness if water conditions are fine?

[jordzcov]

Hi, Over the past few months ive had a range of issues in the tank. When ive had a major issue ive done water tests which all give fine water readings. A few times ive even taken a sample to the fish store to do more detailed tests, and these also come back fine.
Are there some generic things I should maybe consider or keep an eye out for which can be causing issues in the tank outside of water quality? If water quality is fine, what would be causing fungal diseases in the tank? any advice around this is greatly appreciated.


Details:
70L tank
Now holds 3 neon tetras and 5 Harlequin rasboras


Some recent events:

- Fungus appearing on the top fin of a few of the rasbora




- Some tetras developing large bellys, while others look malnourished.






Brought home new Rasbora which saw 3 tertas already in the tank die, as well as 1 new rasbora die over 2 days

[Martinspuddle]

Top two images the water looks cloudy to me.

What are all your water parameters?

[VikingMummy2015]

It can be disease brought in by the new fish. But as Martin says, what are your actual water parameters in terms of ammonia, nitrite, nitrate, gH and pH? How old is the tank and how was it cycled? What water treatment do you use (dechlorinator plus anything else)?

[jordzcov]

Water was a little murky as i moved some plants during the water change, so it kicked up a bit of soil in the tank earlier that day.
ive also recently added bogwood which is the brownish tint

nh3 - 0
no2-0
No3 -5
Ph - 7.5
Kh - 7

Tank is 2 year old and cycled
i add water dechlorinator, and a bit of bio booster each week.
Daily fish feeding and a few drops of plant food
Will do a deep clean of the tank and filters one a month (using the siphoned water), and usually add some tabs for the plants

[Martinspuddle]

Sounds to me stress from the new fish has allowed the health issues to manifest, this is why I advocate quarantine all new stock.

[jordzcov]

hmm, good point. i found it strange for both old and new stock to die, but stress sounds realistic.
with the new fungal issue, im assuming theres nothing i could have doen to prevent that (the harlequin rasbora have been in the tank for about a month now, and only this weekend noticed the white on 2 of them

[plankton]

How do you acclimatise new fish to the tank?

[Lo1]

You may find this interesting going forward, also eSHa products are shrimp safe.




Image courtesy from eshalab.com



Image courtesy from eshalab.com

Thank you for the heads up.

[Martinspuddle]

You may find this interesting going forward, also eSHa products are shrimp safe.



Image courtesy from eshalab.com



Image courtesy from eshalab.com

@Lo1 always make sure you add a image courtesy copyright credit at the bottom when posting such images on the forum.

I know these are downloadable but you've reposted them on a public web forum, as a dear friend use to say me, cover your butt.

[jordzcov]

How do you acclimatise new fish to the tank?

usually just let the bag of new fish sit in the water for about 30 mins/an hour. then every 15/30 mins add some of the tank water to the bag until the bag is then full over a few hours and then sinks/ or once its near ful i tip it horizontal to encourage the fish out while under water