DISASTER!

This is hard. Really hard! Difficult to tell, I mean. This is the story of how I lost all of my Tanganyikans from my 150 gallon tank. Well, not really how I lost them, because I can't say, but the story of the death of an entire stocked tank in a matter of hours. 


Here's how it went:  

I did my weekly PWC on Sunday afternoon, 4-ish, and I do only a 1/3 change because these are sensitive fish and any more than that seems to stress them. My other tanks get 1/2 PWC once a week. I did not disturb the decor or sand at all this time (it remains relatively clean without debris accumulating), but I simply placed the Python siphon hose into the water and started draining, then when it was 1/3 gone I tested my new tap water for temperature match and started refilling, taking care to add the correct amount of Prime. I have to be careful about temperature in particular because, again, they are sensitive and they show it when you are not careful about it. I have a pretty solid routine down, since this is a valuable tank in terms of the cost of the stock, as anyone who keeps or has kept Tanganyikan cichlids can attest. I've made mistakes with Tang cichlids in the past and treated this tank like the prima donnas they were.


Everything went fine, and we went out to dinner. No one was at home while we were out. We come home later and I fed them, and they all ate normally. We went to bed, and when I got up Monday morning everything looked fine, and we all left for work and school. We were all gone all day, with nobody home. When I got home from work my daughter alerted me that some of the fish were lying on the sand. Uh oh. What could this be?


I did a big PWC, thinking that something got into the tank, even though another PWC this soon after the first is risky, but I had to do something to try to save the tank, which was in obvious distress. All members were either dead or dying. Every last one. This included four 3.5-inch Kapampa frontosa, six Paracyprichromis nigripinnis, one 3-inch N. leleupi, and about 10-12 Altolamprologus species of various sizes, from 1.5" to 3". The water tested fine, in that there was no ammonia or nitrite, and very low nitrate (it hardly ever measures much nitrate, considering how small the fish were for this much water). This did not look like a case of not adding enough dechlor, since the times I have done that the water starts to cloud up and you see the params go wonky, and the fish start suffering immediately. I suppose this may not always be how it presents, but just in my own experience. Chlorine present in the water is not something this group of cichlids would take their time to react to, in other words. Cross that mistake off my list.


What then? I tested the pH and the tap water is the 7.6 it always is, with the tank measuring only a tiny bit higher at 7.9. Sometimes I reach 8 but as the tank matures the sand is buffering the water less and less, it seems. At first I thought the tap was measuring way low, at 6.2, but my pH meter needs to be calibrated and the liquid reagent kit proved it to be more alkaline, as always, at 7.6 (I'm sending the meter off to Milwaukee to be properly calibrated, as the adjustment screws are not solving the problem).


Over a matter of hours all fish dead. Monday night I tore the tank completely apart, removing and cleaning all the rocks (there must be 300 pounds of rock!) and cleaning out the sand, then taking apart the filters, a Fluval FX5 and a Rena Filstart XP4 and sterilizing them, loading with all new media. This took hours to complete, and was quite a physical strain, but I could not sit there and look at this giant glass testament to my failure.


What went wrong? What happened to slowly kill off every last fish? I've been over it and over it, and even my husband, who was present during the PWC procedure, can't come up with anything that does not match with my recollection. When I fed them I used the New Life Spectrum cichlid pellet, like always, and this time I did not use any frozen food, which could potentially go bad and perhaps sicken the fish. I think it must have had something to do with the water change, but with these fish any mistakes made in that procedure are typically evident quite rapidly, in my experience, and not 24 hours later.


I suppose I will never know, but I will continue to beat myself up over it, and not only because of the massive financial investment that went down the drain. I feel like I ought to have been able to get this tank mature and grow out the frontosa to their potential size, and this goal is not going to be achieved, at least not in the near future. I just don't have the funds to invest in replacing the fish and starting over. Maybe someday I will git it another shot, but not now. It would be easier to take if I knew what happened, so it could be mitigated in the future, but I just can't think of what happened.


Incidentally, when I did the water change on the 150 I also did one on the 20h goldfish tank in the kitchen, and they never had any problems whatsoever. Not a ragged fin, cloudy eye or red gill in the bunch. That tank, in fact, was cleaned aggressively (this tank was cleaned after I was done with the 150) and I moved decor around to siphon out the copious debris that collects with these filthy fish, and wound up with about an 80% change of the water. This is a typical change for that tank, and the goldfish seem to thrive with this weekly routine. They are fantails, and their fins are in perfect shape, with no signs of any water quality issues. I would not dream of that kind of maintenance on a Tang cichlid tank.


It could be there was something in the tap water that affects Tang cichlids and does not affect goldfish, which is definitely possible - goldfish are known to be much hardier - but I won't likely ever know. Copper leaching into the tap water would affect many species, but with the higher range pH that is less of an issue. If we had soft, acidic water then that would be high on my list.


In the past when I have called the water treatment plant to inquire about certain values (some systems contain levels of NO3 -nitrate- that cause aquarists some problems, for instance) I am usually met with defensiveness, as if I'm trying to blame the water treatment people for health issues, which I'm not. I just like to know what I'm dealing with when I put tap water into my tanks. This is a huge part of the process and I don't have any control over what comes out of the tap. If they said to me, "oh yes, Sunday we registered a higher than normal level of ________ in the system. That might explain it" I'd be grateful and go on with my life. Maybe they could even tell me to avoid doing PWCs on a certain day of the month, perhaps. I just want to be informed so I can manage my livestock the best I can.


So, now I'm setting my sights on a less pricey species from the other side of the world, in South America. I'm going to turn this tank into an "eartheater" tank, with Satanoperca daemon, which sounds awful but actually is the designation of a species of cichlid that is attractive and peaceful. It has been known as Geophagus jurupari, but there is a lot of work being done on the taxonomy of the genus so it covers quite a few species. I have added wood and plants to the tank, but only plants that attach themselves to the wood and rocks, and nothing planted in the sand, because it will be uprooted by these sand-sifting cichlids. I will consider angels and acaras as well for this tank, which are other peaceful cichlids that are appropriate tankmates.


Right now the tank is cycling with some shubunkin (if you have been reading this blog you'll know that I do cycle tanks with fish and I'm not ashamed of it!) and after things have settled in the goldfish will go into a friend's pond. I'm doing large PWCs during the process, and we're about halfway there. The fish are about 3" long and there are only three of them in this huge tank, so nobody needs to get uptight about animal cruelty. I did the same thing with the goldfish I currently have in the kitchen, which started out cycling the 150 themselves a couple of years ago before I added my Tangs, and they are doing great to this day.


I am really trying to move on but will be affected by this traumatic event for a good while. I do feel like a failure but I'd sure like to know what I did. No broken heaters, no electrical shock, nobody spraying chemicals, painting nearby, etc. There was nothing in the water that I have a test kit for to explain it, so I guess it will always be a mystery, and be, to date, my biggest DISASTER!