Only You Can Save Your Fish
Written by Sunday, 26 September 2004 00:00
After writing hundreds of articles answering thousands of questions and spending too much time in various boards and lists on the web, one might think that I am the guru of fish keeping and nothing goes wrong in my tanks - ever. Well, nothing can be further from the truth. The only difference is that I regularly observe my fish very closely so I take notice of any behavioural or appearance changes and thus save some precious time that may be crucial in saving my fish should something go wrong. Recently I had another of those moments when you have to decide within minutes what you are going to do. I decided to share this experience with you only because I think it is a very good example of how your quick and correct action can avoid a tragedy.
On Saturday I made my usual water change (approximately 30% or 330 liters). As usually, the fish were not fed that day. On Sunday night I noticed one of my fish (the male Chilotilapia euchilus) standing at the corner of the tank and not responding as usually to my presence while its colour was a bit dull. I checked the rest of the fish and there were no other signs of strange behaviour so I thought this might be a temporary bad mood of the fish or perhaps it had been chased by one of its tankmates.
However, on Monday morning the tank smelled disaster. All the small and medium sized fish were at the surface whereas the big ones were lying flat on their bellies on the substrate. Even fish that do not stand the presence of each other were lying next to each other, like the two male Nimbochormis.
The signs were clear: something was very wrong with the water. Immediate action was required; in such cases there is no time for further observation.
My first thought was that there had been an ammonia spike because of a dead and decaying fish. I quickly run some tests which showed that NH3=0, NO2=0, NO3=0, GH=14, KH=17, pH=8,3. So it was not ammonia or nitrates. The water was full of small bubbles and both pumps were working fine. The temperature was 25.7oC. The data did not point anywhere.
In these cases a large water change is the first thing that comes to mind. I immediately performed a 30% water change while thinking what else should I do since - clearly - there was something wrong with my water. If that were the case the water change would not help: it was water from the same source I was using to replace the polluted water in my tank. After dechlorinating the water I decided to add a generous quantity of activated carbon in the filter which should remove any organic substance which might be responsible for this situation. I had to leave for work so I thought that I did what I could and I hoped everything would be ok when I would see my fish again in the afternoon.
While at work I kept on thinking about the problem. It seemed quite strange that my fish reacted in two different ways. The smaller were near the top as if there was not enough oxygen in the water, while the bigger ones were lying at the bottom of the tank. One thing was clear: whatever was wrong, it had affected all the fish - even the catfish. Since most of the catfish can get air and overcome the lack of oxygen in the water, I soon concluded that it was not lack of oxygen that caused this havoc. Ammonia was already out of the question, so what?
When I got back home in the evening, things were even worse. The fish were still lying on the sand (small fish near the surface) but the situation of the catfish (especially of my male Synodontis) was considerably worse. A third water change (30% again) did not seem to improve the situation at all.
When you see a Synodontis decorus like this, you know you are in bigger trouble than you thought at first. The fish would not resond to my presence or the presence of any other fish which touched it. I could see it was still breathing but this was not an indication of the possible issue. I noticed that the colour of the fish had faded even more (even the Sciaenochromis fryeri showed some faded spots) while the base of their pectoral fins seemed more red than usual, indicating an irritation. Rushing to the books again I identified the symptoms as a bacterial infection which should be treated with an antibacterial agent. The diagnosis sounded good but it did not quite correlate well with the whole "picture" of my tank and the steps I had already taken to that point. Even if it the cause of this was bacteria, I had changed almost all the water in 2 days so the infection could not have spread so quickly affecting all the fish at the same time. To be more precise, a bacterial infection could be as severe and quick, in theory; yet I suspected there was something in the water, a chemical perhaps.
Anyway, after diluting the number of bacteria that much (if I assumed it was bacteria) I had bought myself some time to try something less drastic than treating the whole tank. After thinking about it a bit more, I thought of chlorine. Chlorine would definitely irritate the fish, would also create this "suffocation" feeling. I had seen a fish jumping out of its tank some years ago when heavily chlorinated water was added to its tank, so this could be it. I decided to add a conditioner with healing agents in it and see what was going to happen. In fact I tripled the dose since I needed some quick effects and my evaluation of the situation was that unless I did something pretty quickly there would soon be no fish left to worry about. Therefore I emptied two more bottles of "aqutan" (by Sera) and left the tank on its own. I had already added the normal quantity of dechlorinator but it seems the amount of chlorine in the water far exceeded the "normal" levels. Anyway, after the addition of the conditioner, there seemed to be nothing else I could do except to sit back and keep an eye on the tank.
After 3-4 hours, the first fish appeared to respond to the presence of the conditioner. Some of them were swimming, there were very few lying on the sand while there was no fish near the surface. Seven hours later, the Synodontis decorus had turned to its normal position while all the fish were swimming normally and some of them had regained their normal colouration. Of course, some of them were still heavily breathing but the overall situation in the tank had changed. The two Glycopterichthys gibbiceps were moving normally now while one of them was also grazing on some algae. At that time, I did not know if I had saved the fish - all I knew was that they seemed to improve, thus giving me some more time to think the situation over. When the lights went out, I just prayed I would see the fish doing well in the morning (hopefully as they used to be).
When the morning came .. the answer was there. As you can see, the fish still seemed a bit better but the water was extremely cloudy, despite the presence of a huge quantity of activated carbon. It appeared that the diagnosis based on my book was right side; though, to this point, I had not medicated for bacteria, the huge water changes diluted the amount of harmful bacteria in the water thus (hopefully) keeping damage to my fish to a minimum. Changing the water once more was simply pointless. The cause of the harm was now identified.
I decided to avoid Furamor and go with something milder. As you already know I keep a huge amount of chemicals and medications at my home "petshop", just to be prepared for moments like this. I chose General Tonic by Tetra Medica which had worked for me in the past. Of course, with 1000 liters of water to be treated, you do not measure in ml but in bottles. Thank God one bottle was more than enough. The calculations showed that I was overdosing by 25% which is in accordance with my treatment habits. After all, I could not add more even if I wanted to. The activated carbon was removed before the addition of the medication of course. I also took a note to replace the medication the soonest - my stock is of paramount importance to me and my fish.
After 10 hours, the water was a bright green colour (well, at least it was visually interesting) and the fish started to show some signs of real improvement. Even the fish that were previously breathing heavily were now breathing a bit better. Of course the situation was still far from ideal but it seemed we were on the right track. Needless to say I did not feed the fish during the last two days. I simply felt that adding nutrients in the water column would add parameters that could mask the causes of the disease. After all, two days of fasting could only do some good to my fatty fellows.
The tank still looked green one day after the addition of the medication. Though less attractive, the sign of recovering fish made it the most beautiful tank in the world; at the end of the day "beauty lies in the eyes of the beholder"! I was more optimistic now but still worried. One thing that really puzzled me is how is it possible to have such an extreme growth of bacteria within 24 hours despite an almost complete water change. Even if the problem was to be resolved still the main issue was to learn something from this incident.
There were many more questions puzzling me. Where did these bacteria come from? How did they manage to multiply so quickly? It must have been something in the hose; something definitely added to the tank during the last water change. Since I rarely put my hands in the tank (even feeding is automated) it should be the bacteria must have come either via the hose or via the water. The strange thing was that this hose was used to make the water change in my 500 liter tank first and then transferred to the 1300 liter tank. Although I inspected my 500 liter tank very carefully, there was no sign that something was wrong there. Anyway, the important thing for the time being was to save my fish and then worry about the rest.
After two days I decided it was time to feed the fish - half the normal quantity. This is also a good check point. Cichlids love to eat. If they seemed unwilling to rush to the food this would be a sign that we would have a long way to go until they were fully recovered. Thankfully, when the food hit the water the fish behaved like they had never seen food before. The results of the two day fasting period were evident. The food was consumed in no time. Sometimes I laugh when I remember the usual instructions "feed only what your fish will consume in five minutes". Those fish will eat me in five minutes!! Everything seemed to be close to normal again. Close inspection of the fish for the next 3-4 days was a must - and there are very good reasons to do that - as you will soon see.
There is always a good reason to watch your fish carefully. However, whenever you face a tricky situation about which you know very little, only close observation can save your fish or prevent further serious problems. We have already seen that - for an unidentified reason - there was a tremendous bacteria bloom in my tank, which seemed to affect all fish in different ways, including their respiration. After taking some measures I saw that the respiration problem was partially treated, but was that all? When treating a tank hobbyists always hope for the best and tend to relax and consider the problem to be over as soon as one of the symptoms disappears. Regrettably, more often than not, this is not the case.
A couple of days later, still observing the tank to confirm full recovery, I saw a small Aulonocara with a swollen belly. Since the swelling was not very evident I decided to wait one more day (I will never know if these 24 hours would have made a difference to the life of the fish which eventually passed away). The day after, the same fish had a much worse swelling; its eyes were also protruding and it had the shape of an oranda goldfish. As if this was not enough, a male Aulonocara showed the first signs of a swollen belly. Both fish refrained from eating which is already bad news. It was evident that the bacterial infection was still not fully treated. Perhaps there were no bacteria left in the water column but the fish were definitely infected. I usually do not rely on aquatic products to treat my tanks but this time the problem was too big to handle in a different way.
It was possible the fish were suffering from Malawi bloat or an internal bacterial infection. This did not change the recommended course of action. Since the fish were not eating I had only one option: an antibiotic which would enter the fish's blood stream via the gills (here is a good point to emphasize the need to read, read and read). Well, fortunately there is such a medication. Unfortunately it is an expensive drug. Still worse, I had to treat the whole tank (1300 liters of water) since I did not know which fish were infected. The fact that only the small fish showed the signs of the infection could well mean that the larger ones were still trying to fight it off. To make things even worse this particular medication is used at a very high dosage (250 mg / 40 liters) therefore I needed a considerable quantity of it. Of course this is never an issue for me when my fishes are at risk, but it would surely make a difference for a number of hobbyists. A final note: this medication is marketed for human use since a special medication for aquatic use costs three times as much!
The medication of choice was of course Minocycline hydrochloride (trademark "Minocin" in Greece, by Lederle). The photo above shows the basic equipment used when I have to treat my fish with a human medication. If the volume is too small I may opt for the injectable form (which saves time and effort) but usually this is an expensive option. This is because injectable solutions have to be freeze dried and sterilized, which adds tremendously to their production cost. Thus, the most common starting material is either capsules (best) or tablets (a bit more work for you). I do not use any special equipment (like special filter papers or vacuum filtration) so the method presented here can be used in any home. All you will need is the medication, two large glass containers (about 1.5 liter capacity each), a spoon with a long handle and some coffee filters.
The photo above shows the 100 mg Minocin capsules. The capsules of the Minocin 50 mg / cap are all orange as you can see below. All you have to do (to begin with) is to take each capsule over the first glass container in which you have already added about 500 ml of water. Take the two pieces of the capsule apart and let all the content drop in the water. Do not drop the capsule covers in the glass container (see photo below).
Here are the gelatine parts of the capsules. If the two parts are not differently coloured you shall always keep the capsule with the larger gelatine part down (vertically) and carefully remove the smaller one. This way all the contents will stay in the larger part. Alternatively you may just open the capsule on top of the container with the water, so all the contents fall directly in the water.
Once you have dropped the content of 15-20 capsules in the glass container (according to my calculations I needed 6600 mg or 64 capsules of 100 mg) you mix the water and the medication well, stirring the solution with the spoon. What you get is a cloudy yellow solution with lots of foam on the surface. If this solution is dropped in your tank it will create exactly the same thing in a larger scale. A cloudy tank with tons of foam on the surface. Air pumps (always necessary when treating a tank) and powerheads or filter pumps will only make things worse. Soon you will have to spend half your day over the tank removing the foam to reduce the risk of your fish suffocating. In any case, the foam is totally useless for treatment; it is not created by the active ingredient (which is only a small part of the contents of the capsule) but by the excipients which should better stay out of your tank.
Here is where the humble coffee filter becomes useful. Always place two filter papers with their hard bottom parts perpendicular to each other so they do not collapse when they become wet. Some medications may make the paper too soft and open holes which will ruin your effort. As more and more solution is coming through, the filter will clog and the flow will be reduced. If it is reduced too much just throw the filters away and replace them with new ones.
Now you are ready to use the filtrate. This method works perfectly well for many human drugs like tetracycline, metronidazole etc.
The treated tank as it looked 24 hours later. Since minocyclin is light sensitive the lights were reduced to just two tubes (out of the six which are normally used in this tank) while the duration of lighting was also reduced to 2 hours (down from 8 hours). Still, ambient light was enough to change the bright yellow colour to violet. Because of that, I added some new antibiotic every day. The initial dose (according to the books) was approximately 6.5 grams of minocycline. My usual approach of overdosing was used so I started with 7.2 grams - assuming a net water volume of 1000 liters (day 1). A day after, I added 0.3 grams more (day 2). The next day one more gram was added (day 3). The tank was left in peace for one day (day 4) and then water changes started. I made two water changes per day (30% each) during the first two days. After the last water change a generous quantity of activated carbon was added to the filter to remove the residual quantities of the medication.
Did I manage to save all the fish? Of course not, this would be to much to expect. However, the number of casualties was far less than I expected - in addition to being odd. Two catfish were lost, a 30 cm Pterygoplicthys gibbiceps and one of the two Scobiancistrus aureatus. I also lost a small female Aulonocara stuartgranti. Out of the six fish with swollen bellies and protruding eyes only one was lost. The rest responded remarkably well to the treatment and showed signs of improvement almost immediately. I still watched them very carefully until I was sure they were 100% back in shape. Out of 10 fishes which refrained from eating 8 resumed eating during the last days of treatment while one started taking a bite every now and then a couple of days after the end of treatment. By the end of treatment the water was clear and all the fish manifested an absolutely normal behaviour.
The bottom line of this article - apart from the information which you will hopefully find useful - is that only you and your quick reactions to abnormal situations in your tank can save your fish. This should always be in your mind. An infection in a tank is like a time bomb: it may explode any second. It therefore needs to be treated in a timely manner as it will only escalate and get more complicated (for instance, by causing secondary infections) the more it is left untreated. No matter what technical support you use to prevent a disease outbreak in your tank (UV sterilisers, ozonizers etc) there is only one thing that will make the difference between a healthy tank and a disaster: your presence and attention.
Photos by the author.
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