Oops rookie mistake!

[JamieB215]

I wouldn't call myself an expert by any stretch of the imagination but I have been at this long enough to know better than to add the LFS water when adding a new arrival! Doh! It's been awhile since I got a new fish and wasn't thinking. So here's the scoop

37 gallon tank had a cory cat, 2 neon tetra, 3 hatchetfish, and 3 red minor tetra. Established going on 6 years. All water parameters perfect per API liquid drop test, regular water changes with Stress Coat+, Aquaclear 50 filter, and no major illnesses besides a bout with ick which I managed with a couple casualties last year. AND THEN...

About a week ago I got an itch for a new fish a rubber lip pleco caught my eye. Brought home, acclimated, and introduced. Like I said I spaced and just dumped him in instead of netting him. So fast forward to today. I now have a cory cat and 2 neon tetra left. I'm sure I brought something home from the LPS but not sure what. I returned the rubber lip for a refund even though he didn't look or act sick. Had them test my water and they came up with the same as I did. Everything as it should be. Did a partial water change just to be safe. added a little extra stress coat, and began treating with maracyn two.

What else can I do to save the last three? Also if I get home tomorrow and I have lost them all where do I go from there? Never had this happen Thanks in advance for the help.

 

[Angellove78]

I'd vacuum the bottom, basically clean your tank. And do another 50% water change. You never know what's in that stores water. And it's better to be safe than sorry. I'm no expert either, but thats what I'd do.

 

[coralbandit]

Were the fish lost 6 years old ? If so that is not too shabby...
Complete the full dose of the Maracyn as per instructions so not to build up a resistant strain.
How are the remaining fish holding up?
Do you know your PH/GH ? Maracyn can have issues in hard water and even becomes toxic if expired.. Here is some info on Minocycline [Maracyn 2]

MINOCYCLINE:
USE: Minocycline hydrochloride, also known as Minocycline, is a member of the broad spectrum tetracycline antibiotics, and has a broader spectrum than the other members, especially as to gram negative bacteria where Minocyline has more activity (albeit still limited effectiveness when compared to other gram negative antibiotics).
Minocycline is also synthetic whereas Tetracycline Hydrochloride and Oxytetracyline are naturally occurring. It should also be noted that Minocycline maintains serum levels 2-4 times that of most other tetracyclines (150 mg giving 16 times the activity levels compared to 250 mg of Tetracycline Hydrochloride at 24-48 hours).
It has excellent anti-inflammatory properties which makes it a good choice for septicemia, although for Viral Septicemia there is no effective treatment, only prevention.
Minocycline is also effective for fin/tail rot and OCCASIONALLY pop eye and is sometimes suggested for dropsy. However as for Dropsy I strongly recommend against this as this antibiotic can cause severe kidney damage, which is the last thing you want with a possible Dropsy case.
However Minocycline (Maracyn 2) is not generally a good first choice for fish with sores; Nitrofurazone, Sulfa Products, and Neomycin are better choices for sores/wounds.
For more about Dropsy, please see this article:
Betta with Dropsy
Minocycline is also skin absorbed like Kanamycin (although not as well) which can increase effectiveness. It is also nontoxic to invertebrates but should not be used in Marine aquaria.
Minocycline (like other Tetracyclines) is easily absorbed by calcium, making this a POOR choice for saltwater or high GH freshwater aquariums (such as African Cichlids, livebearers), in these cases Kanamycin is the better choice.
The above point is often missed by well meaning aquarists (often in many forums that love to recommend Maracyn-2).
The reason is that although Maracyn–Two (Minocycline) is a good product/medication when used in the right conditions for the right problem (of which it is relatively wide spectrum), the problem is that most aquariums I have either encountered or have been sent the water parameters for (emailed, etc.) have too high of a mineral level (GH over 200) for Minocycline to be truly effective.
In fact there in lies the problem in that often these same minerals that render Maracyn Two less effective, can IMPROVE the fish’ natural ability to fight disease (via better osmoregulation & Redox).
See more: Do Fish Drink, Osmorgulation
Another note about the dangers of Minocycline as with Tetracycline, is that Minocycline becomes dangerous past its expiration date, in other words expired Minocycline can become more toxic over time.
With these points in mind, generally the ONLY aquaria I recommend Minocycline in are Amazon River tanks such as Discus Aquariums.
DOSAGE: Maracyn-Two is the primary source for this anti-biotic, follow directions given by Mardel (manufacturer of Maracyn –2)

 

[JamieB215]

Thank you for the quick replies! The hatchetfish were all added at the same time about 5 years ago. I will continue with the treatment and water changes per the instructions and keep my fingers crossed. Thanks again!

 

[coralbandit]

Common life span of hatchet fish is 5 years so you have done well by them .
Sometimes opportunistic infections will strike weak and old fish without effecting others ?