Loaches and salt tolerance

[squid]

Just lost 3 pcs of my big clown loaches a few days ago. I was not able to pinpount the problem.
tested and no ammonia, PH is a bit highh at 8.
I'm not sure what happened, during the weekend i was not able to check on them, I have 10 pieces in my 300 gallon with some arowanas,
what happened before was i was transferring some arowanas from thsi tank to another tank, So I had to remove 50% of the water.
after I removed the water, I added water conditioner, this is my usual practice for water change. then i added back tap water.
i left in the morning i found 2 pcs of my biggest clown loaches already dead





I'm still not sure what could have caused this. there was also a typhoon, so might be due to temperature drop?
when i found the 2 dead they were covered in slime. Also noticed my pleco had reddish like wound on him 3 days before. not sure if this is the cause for my loaches death? a day after i lost 1 more clown loach, I've had them for 5 years . I have 10 pcs in all but lost the 2 biggest ones.

I have treated their tank with antibiotics and the rest dont show any problems at all. but i have stopped feeding for now, only adding a little amount of pellets.

I'm just curious how much salt loaches can take, My arowanas also encountering some issue right now, they seem to be shedding slime.
I've added salt to my main tank with arowanas , concentration of 1 tablespoon per 5 gallon , I live in a tropical country so i dont usually have heaters in my tank, but i've added them to my tank now. I have some Kubotai loaches and yoyo loach in my tank, so far they dont seem affected by the salt concentration, I'm just curious if anybody has tried to have higher salt concentration on their tanks?
I'm thinking of adding salt to my other tank as well this rainy season?

[plaalye]

What is your water source? I would suspect changes there, possibly caused by heavy rains. What is your typical ph? Test the ph, kh, gh, and TDS of your change water if you have the means to determine if there has been a sudden change. There could also be some sort of chemical contamination in your water supply. I personally wouldn't be adding salt, or anything else, until I identified the source of the problem. If it is an issue of osmotic shock salt may further complicate matters. Sorry for your loss.

[Diana]

1 tablespoon per 5 gallons is a LOT of salt. Most Loaches are not very salt tolerant. If it must be used (good Ich treatment) raise the level slowly, over several days and do not go more than half what you did.

Excess slime coat (any species) is a sign of irritation. Something in the water is not to their liking. Could well be salt. Or, if the water has changed its mineral content that could be part of the issue.

Doing such a large water change is usually only safe if the new water is very similar to the old water. Same GH, KH and TDS.
If the typhoon stirred up a lot of mud, or washed a lot of minerals into the main water supply this could be a problem. Conversely, if the typhoon dumped a lot of rain into the main water supply then it would be much lower in minerals than the fish were used to. This is even harder for the fish to handle than increased mineral levels.

The typhoon might have washed a lot of nitrates (from agriculture) into the water supply. This would also stress the fish. If the water company knew about the possibility of contamination they might have increased the amount of chlorine or chloramine, so the dechlor you added might not have been enough.

So there are many possibilities, and unless you have been testing both tap and tank water before and after, you might not know what really happened. Even with testing it may remain guesses.

[squid]

thanks! , yup might be the typhoonm which messed up the water supply lost 2 of my biggets and a 5 incher.
so far the others are normal. I added a heater into the tank, but i'm still a little hesitant to do water change even a little as the water is quiote cold
its been raining 3 days non stop here.

[Diana]

When I use rain water I will heat some on the stove to blend it with the cold rain water so the end result is water that is pretty close to tank temperature.