New fish-Partial slime coat slough off

[discusdave]

Hi everyone,
I bought 15 3 inch or so discus from a LFS. All are nice and healthy looking. I have them in a BB 75 gallon tank. Two days ago I did a 50% water change out of the tap, dechlorinated with same temp. My tap is about 45 ppm TDS, so it is very soft. I noticed last night that one of the fish had some grey patches on his slime coat. Seemed a bit darker than normal. This morning I am seeing the same fish and those areas have sloughed off. As a matter of fact I think I saw them floating around the tank last night, but thought it was some film out of the cannister filter tubes.

This fish is still inquisitive and swam to the front of the tank this morning. I can see where the coat is absent, but his scales and skin look good.

I initially thought columnaris, but this fish hasn't gone downhill or anything as quickly as descriptions of this disease would have it.

Could my large water change have done it? pH is 6.5. Temp 85. Good filtration (Eheim 2028 Pro II and two Hydro sponges).

I'm just trying to figure out if I have a sick fish that needs medicating, or if I have a fish that was stressed (by the WC) and is now recovering? He seems to be eating right now.

I guess what I don't want to do is medicate unnecessarily. I can put a portable UV on the tank for a while and closely observe the fish.

Any advice would be great. Thanks.

Dave

[sidra]

Hi Dave,

I'm sure Carol or someone will reply to you soon. In the meantime, post pictures if you can and check out the Simply Discus library. Click on the Diseases section and then clilck external parasites section and check out the Costia and Chilodonella photos. I'm afraid to give advice at my low level of experience, but I just wanted to point out those photos to you. I used them to identify a problem I had with my fish.

Kristen

[jeep]

Two days ago I did a 50% water change out of the tap, dechlorinated with same temp.
Dechlorinated water change from tap... straight into the tank? How about ph from tap vs. ph in the tank???

A 50% water change straight from tap can cause problems if the ph is different from the tank water. Also, the co2 in tap water can be an irritate the slime coat. I would suggest you always age your water overnight when doing that large of a water change.

In the mean time I would add 1 TBS of salt per 10 gallons to help build the slime coat back up...

[discusdave]

Thanks for the advice guys.

Jeep, I added the salt as you advised. I think I will break up the water changes into smaller daily amounts.

I am going to observe the fish for right now. It seems OK except for the areas of slime coat that sloughed off.

I have an automatic water changing system on my other tanks. I might try to hook this one up as well. My system adds small quantities several times daily.
Dave

[Carol_Roberts]

You really need to check the pH of a cup of water directly from the tap and the same cup of water 24 hours later (after it has set on the counter overnight). My tap is 6.8 and tank is 7.8. As you can see a 50% water change would lower the pH to 7.3 in minutes. This can cause acid burns on the discus.

[discusdave]

The fish looked so much better this evening. Looks like the slime is building back up, and it is clear. color is normal and he is eating. Whew! I hate it when my ignorance/mistake makes my fish suffer. I'll not do right out of the tap changes again, but will match pH/temp and age the water a bit from now on.

Great forum. I'm glad I registered. Great help.

One other question: Is there any value to keeping a certain level of salt in the water on a continuous basis as a prophylaxis?

Best regards,
Dave