Hi again. We last communicated sometime late last August.
I'm happy to hear the fish's ulcer healed.
I can sympathize with your reluctance to treat what the local store referred to as "blackening disease" because #1) it is quite rare and #2) the fish is not displaying one of blackening diseases primary symptoms which is an inability to swim correctly, swimming in a whilrling "corkscrew" motion.
I belive there are 2 possibilities here and they are an unfavorable reaction to something in the water and possibly a secondary infection. I tend to lean towards something unfavorable in the water as the problem.
I rememeber you had mentioned that the tank was fairly small so what I'd like you to do is start off by changing 1/2 the water in the tank using dechlorinated water that is the same temperature as the water already in the tank which should be in a range of 16c-22c degrees.
Right after the partial water change add 1 tablespoon of aquarium salt or any other type of salt that does not contain iodine.
Once the above has been done add a product to the water called Stress Coat, click on this link, http://www.edirectory.co.uk/pf/mia/d/api+stress+coat+30ml/pid/10289920 ,
for a view of the product. It contains the natural healing ingredient aloe vera. Just follow the directions on the product label for dosage instructions. It can be used on a continuing basis and is ideal to add when doing water changes.
Seeing that you have a small tank with 2 fish, if I recall correctly, it would be best to change at least 1/4 of the water every 2-3 days or 1/2 the water every 4-5 days.
This will prevent toxins from accumulating in the water. Keep in mind a filter alone cannot maintain an aquarium. Partial water changes are an absolute necessity in order to maintain fish health. It's also important to not overfeed the fish. Feed only a small pinch of food once a day.
If you follow my recommendations thoroughly and the greyish coloring on the tail does not begin to subside within 10 days then please let me know and I'll recommend an appropriate medicine. At this point in time I concur with you in trying to avoid the use of medicines.
Warm regards.
Ric
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Yes the Aqua Plus is similar to Stress Coat with the only difference being that Stress Coat contains aloe vera whereas Aqua Plus doesn't but as you've mentioned, Aqua Plus does contain valerian root plus other pure herbal extracts so I think Aqua Plus and Stress Coat are interchangable.
The fact that the fish is behaving normally is a good sign and I wouldn't worry about the occasional rests it takes (just floating idlly near the water's surface).
As for the tank's size. Taking into consideration at this time the size of the fish I think you'll be fine as long as frequent partial water changes are done as recommended in my prior post. Please note that the lower the fish to water ratio is, the easier it is for the water quality to deteriorate.
The ideal set-up for housing goldfish is to allow 80 litres of water, minimum 40 litres, per goldfish. Keep in mind that most goldfish will grow to be at least 15 1/2 centimeters and some even get as big as 30 centimeters. So it would be advisable to consider some time in the future housing the fish in a bigger tank.
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