NO INFORMATION OFFERED TO CUSTOMERS
Yes, I have killed thousands of fish over the years. When I first started fish keeping, nobody would tell you how to keep them. You went to a pet shop, bought a tiny fish bowl or a small aquarium, gravel, plastic or live plants, (filter & pump if you got a tank) and a bag of water conditioner (rock salt stained blue with Methylene Blue). You also bought as many fish as you wanted and went home, set it up and put the fish in the tank straight away. It's amazing any survived. Most died within a few weeks from ammonia poisoning, but we didn't know about the ammonia/ nitrite filter cycle because nobody would tell us about it. Most shops didn't even know about it.
If you bought live plants, most were marsh or garden plants and you weren't told to get a light for the tank. Most plants would rot within 2 weeks of having them so you went back and bought some more. Eventually you give up on live plants and get plastic ones.
If a shop was willing to offer advice, it was to catch the fish out once a month and put them in a container of tap water. Take the tank outside and hose it all out. Then set it back up. You didn't get told about partial water changes or the filter cycle. It was a free for all with shops selling you whatever you wanted and expecting you to lose the fish. When it came to fish nets, the shop would sell you a little net (2-3 inch) and you would get annoyed chasing a fish around with a tiny net.
It wasn't until I got a book on marine fish in the mid 1980s that I learnt about the filter cycle. One chapter in a marine book turned everything around and instead of losing fish on an almost weekly basis, I actually kept fish alive for months and even years.
I started keeping rainbowfishes and other Australian native fishes around that time and there was virtually no information about their care & keeping in captivity. In fact most rainbowfish sold then were wild caught and only a few species turned up on the market once every 6-12 months. As for the other native fishes, it was go out into the bush and get your own. It was make it up as you went along. You tried different things and some worked and some didn't.
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DISEASES
When it came to diseases, most medications killed the fish because a lot of native fishes are sensitive to chemicals, and there weren't clear directions on the packaging, and if there were shops were selling tanks as x gallons, but in reality they didn't hold that much water. With rainbowfishes, they need plant matter in their diet or they get all sorts of health issues. It took years to work out their dietary requirements and which foods we should avoid. This is back in the time when beef heart and liver were sold as standard frozen food for fish. Not that I used it as a staple but I did use it a few times.
eg: My 4 foot marine tank contracted white spot from a fish I got from the pet shop. I was sold a copper based medication (which was standard treatment for white spot in fresh or saltwater tanks back then) and told the tank held 50 gallons. Yes an empty 4ft tank held 50 US gallons but when you had substrate, rocks, etc, and the water level was a few inches from the top, it held less than that. Some of the medications were also made in the UK, and UK gallons are different to US gallons (4.5 litres in a UK gallon, 3.785 litres in a US gallon). I was using a UK made medication and treated the tank for 50 gallons and wiped out everything in it. Within an hour of treatment everything in that tank was dead. I wasn't told copper was toxic to invertebrates and the shrimp, hermit crabs, starfish and everything died. I wasn't told how to work out the volume of water in a tank. We were simply sold stuff so the shop could make money. There was no internet either and libraries didn't have many, if any books on fish keeping.
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SHOPS LOSE FISH
Shops expected you to lose fish and didn't care. If you lost a fish and took it back to complain, they just gave you another one. They didn't try to work out why it died, just swap it for another and send you on your way. Shops even lost lots of fish. When I first started working in the pet industry, we used to lose about 75% of the fish we had in stock. Every week we would drain and flush out the tanks, squeeze the sponge filter out in tap water (or change the filter media in a box filter), then fill the tanks with tap/ water, add blue salt (see above) and the following day we would get in a huge shipment of fish, add them to the tanks and try to sell as many as we could before they died.
After a few weeks of fishing out bodies and watching tanks full of fish die from ammonia poisoning, I asked a co-worker why we were doing this (flushing out tanks and killing filter bacteria). He said because that is what the boss told us to do. I said it's wrong though, my co-worker agreed. I said if I speak to the boss about this, will you back me up, he said yes. So we had a chat to the boss and after lengthy negotiations we were allowed to try something different on two tanks. We didn't flush the tanks out and didn't wash the filters out. We did partial water changes and monitored ammonia and nitrite levels and kept two tanks of fish alive for over a month. This wasn't enough to convince the boss so we were give 6 tanks to try this on and the tanks had to have the same fish in as tanks the boss was maintaining in the usual way. No worries. We did our thing on 6 tanks and the boss looked after her tanks. She lost everything within a week and a month later ours were all still alive. We were given a bank of tanks (about 12 tanks) to try this on just to make sure it wasn't a fluke. We did a bank of tanks and lost very few fish compared to the other tanks being maintained the old way. That was enough proof for the boss and we then changed the way we kept fish in that shop. We went from losing about 75% of the stock within a week, to losing about 5%, and the 5% we did lose was due to disease.
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GRAVEL CLEANERS, BETTER THAN SLICED BREAD
Around this time I was cleaning the shelves and came across a gravel cleaner. There were two on the shelf and they were covered in dust. I asked the boss what they were, and she showed me. I said why aren't we using these. I said can we use one in the fish room? She said yes. I used the gravel cleaner in the fish room and within 5 minutes of using it, a customer saw me and asked what I was doing. I explained the gravel cleaner and the customer said "what a great idea" and they bought the other one. The boss ordered 2 more in and they sold within a few hours of being at the shop. The boss ordered 4 more in and went to the supplier to get them. They sold about 30 minutes after coming into the shop. I told the boss to get a dozen of them and she did. They sold within a day. Every customer that saw the gravel cleaner being used, bought one. Prior to this, everyone used to empty their tanks whenever (once a week, once a month, a couple of times a year), carry them outside, wash them out and then set them up again. The gravel cleaners had been around for a few years according to my boss but nobody had heard of them. Within a month of me finding out about them, we were selling over 100 each week. It got to a point where the boss ordered in a crate full at a time and we would sell 1000 gravel cleaners in 1-2 weeks. It was crazy.
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EUTHANISING FISH AND OTHER ANIMALS
When fish were sick I got the job of euthanising them. When customers brought in sick fish and wanted to find out what was wrong with them, I got to euthanise the fish and dissect it. After killing a few hundred sick fish, you become cold and just kill without feeling or thinking about it.
The combination of euthanising fish and other animals at the shop, experimenting on my own fish when they were sick because there was no treatment or even diseases that presented like the ones I was seeing, and taking care of thousands of new fish coming into the shop each week, left me with blood on my hands. The blood was added to from all my birds I lost during the cat war in the late 80s and early 90s.
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CUSTOMERS NEED TO KNOW HOW TO KEEP FISH
When I started working in the pet shop, I was determined not to let customers go through what I went through. I would spend as much time as needed talking to customers and explaining the filter cycle. I told them to set the tank up, wait a few days (or a week is possible) and then get a couple of fish. I asked them to bring some tank water in for testing on a regular basis and we tested it for free. I wrote the results down (in numbers) on the back of a shop card or piece of paper with the date and test results. I asked the customers to bring the paper with results in when they brought water in to be tested so we could compare the results and see how things were going.
When customers needed to know how much medication they needed to treat the tank, I wrote a formula on the back of our shop card so they could work out how much water was in their tank. I also asked what fish were in the tank and tried to get a medication that was safe for all of them.
Talking to customers and informing them of the basics of fish keeping concerned some of the bosses and management because I was apparently spending too much time with the customers and not enough time cleaning tanks. I managed to keep the tanks clean and it didn't stop me talking to the customers. Within a few months of me being at that shop, we had repeat customers coming in with friends and relatives to buy more tanks and fish. This did make the bosses happy and from then on I was allowed to talk to customers for as long as it was needed.
We had customers keeping fish alive for 6 months or more and breeding them. They were happy because prior to getting the information from me, they were losing fish on a weekly basis like the shop was. And it wasn't just a few customers keeping fish alive for a long time. Virtually all of our customers started keeping their fish alive for years. The number of medications we sold dropped right down, while the number of test kits and gravel cleaners went up. And I found an actual dechlorinater, which I sold instead of Methylene Blue stained salt.
It turns out I developed quite a following with customers coming in specifically to talk to me and some even waited hours to talk to me about their fish. When I left that store, half the customers left it too. Most of them managed to track me down at another store.
For everyone who has killed a few fish, it happens, especially if you aren't informed about how to keep them in the first place. If you have concerns about losing a few fish, that's good because it means you care. But don't dwell on it because it won't help your remaining fish. Work out why the fish died and fix that issue, then enjoy the remaining fish. You are in an age where the information is readily available and there are a lot of people who are willing to give you that advice for free. If you have questions or are unsure about something, start a thread and ask. The worst that will happen is you don't get a response, the best that will happen is you could learn something.
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