Your worst nightmare!

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New Member
Sep 8, 2023
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Cambridgeshire, UK
Hi everyone.

When my daughter wanted to spend her Christmas money and get a tank I physically cringed. I have never had a successful setup and I certainly didn't want to kill any more fish, poor things. I tried to dissuade her but, with Mum on her side I didn't stand much of a chance. This all took place over the phone while they were at the store.

They arrived home with a small, 6-gallon tank, some gaudy blue gravel, plastic rock (cave), heater, basic filter and some tap safe and tank starter. I set it up and left it to do it’s thing as per the store’s instruction. A month later, we went back with a sample of the water. All looked good and we arrived back home with what I think were a couple of Barbs and a female Betta. They went fine for a couple of weeks and then, in what is probably a record for me, they all died one after the other. I know! Hate me! I did give a warning in the title.

I hate dead fish. It makes me feel guilty and awful. I was ready to retire the lot until my wife reminded me that it was my daughters Christmas present, and I should really try to make it work for her. With that guilt in play, I purchased an expensive test kit to see if I could work out what had so quickly killed off the fish. I also started reading and watching all manner of online material, which added even more confusion.

The test kit arrived. The water parameters were all good except the carbonate hardness which was off the scale and the PH was high, around 7.8. I tested our tap water, and the carbonate hardness was the same and PH possibly even higher. I also learned my temperature was too high at about 80F which I have now dropped to 75. After some more online research and more confusion, I decided some acid buffer and a live, heavily planted tank would be the way forward. I was reasoning that the acid buffer would get the parameters closer to where I wanted them as well as providing CO2 for the plants.

I cleaned out the tank and started again with some store brought aquarium soil, some fine gravel purchased online and some low CO2 plants and moss purchased online. I also purchased a more powerful filter, still the simple submersible type that sticks to the glass. I setup up the tank, gravel over soil to about 2.5 inches, plants in and the moss super glued all over the old plastic cave. It didn’t look half bad.

2 months later the plants were visibly growing well with some of the taller coming up out of the water. The water was clear, and parameters were good. All except the PH which fluctuated wildly low when adding my acid buffer treated tap water before bouncing back to a normal range a day later. I decided I could not add fish to this regime so ventured back into the store for a chat. A nice chap got chatting and described the local water as horrendous for fish keeping and recommend using RO. I was surprised they supplied refillable containers of RO instore at a reasonable price. I did a 50% change with the RO and left the tank for another month to ensure everything was stable.

Happy my water issues were now solved, I purchased a sparkling Gourami, 2 Khuli Loaches at my daughter’s insistence and a Pygmy Corydora. Fingers crossed, into the tank they went. A second sparkling Gourami came home as well, he had swum into the net at the store when catching a larger one and my daughter had exclaimed that it must have wanted to come home to the tank as well.

Expecting the worst, I watched the fish like a hawk, looking for any sign of the usual. It has a lot of plants and with the mossy covered cave, there are a lot of hiding spots. After a day or two I lost sight of the Corydora and hoped it was just shy and hiding. The smaller Gourami was not looking very happy being constantly chased by the large one and often found hiding on top of the filter. I probably should have removed the second Gourami at this point, I was hoping they would settle down. I think it was about 3 weeks later, I lost sight of the small Gourami as well. Out of concern and fear of possible dead fish sending the water bad, I decided to investigate.

I drained a little of the water, removed the filter and rock/cave and started searching. The large Gourami and Khuli’s seemed fine, no sign of the other missing fish. Had they jumped out? I started searching around the plants and found a strange mass. Pulling it out with tweezers I found it was what was left of the smaller Gourami. At this point it was a tiny fish skeleton with a little bit of meat left on. I am guessing the Khuli’s made a meal of it after the poor fish had succumb to the bulling. Oh! And I finally found the tiny little Pygmy Corydora which fell out of the back of the filter when I went to clean it. How on earth it got stuck like that I have no idea, there really isn’t any space between the little plastic vents, maybe pump pressure held it there.

I put the tank back together and, touch wood, the 3 remaining fish are still fine 6 months later. This is not the end of the drama though. With the tanks reduced numbers and the fish being of the shier variety I decided a couple of colourful guppies would add a bit of additional life to the tank. WIth the Guppies added it became apparent that they were both in the business of taking nips at each other. I thought again, it would be something that would settle down. It didn’t! Several months later and both with somewhat tattier fins, the smaller of the two succumbed to the constant fighting. Yep! Add another unfortunate fishy death to my name.

The tank is now doing well. The plants are still growing. The water is stable, and the remaining fish all look healthy and are getting bigger. The two ‘Coolies’ are a favourite often making an appearance in daylight. The Gourami has grown quite large and taken ownership of the cave. It will sometimes dart out of the cave to chase the guppy a short way if it gets to close. Observing the behaviour, it almost looks like the guppy goads the chase before swimming away to safety. Both fish have a history of violence!

If you are still here thanks for reading my fishy saga. Hopefully you are not hating too much. I have learned a lot. Small tanks are tough, and most fish behave badly in smaller spaces and when in smaller groups. I have more confidence now and would like to start on a much bigger 70 or 80 gal project with a CO2 rig. Maybe next year. The tank is now my project and, I dare say passion. The reason for the tank, my daughter, now seems bored of it and barely gives it the time of day. I guess that is typical of most kids.
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Welcome aboard matey, we've all lost our fair share of fish, particularly in the beginning of our journeys! There's a wealth of knowledge and experience amongst the members here and we'll have your tank flourishing in no time 👍🏻

Some starting points, regarding tank size...the bigger the better! More room (volume) for error. Big water changes every week, I like to do 50%. And lastly, probably the most important for me at this point...keep fish that are suited for the local water instead of trying to make the water suit the fish. I too have very hard water, so I know the frustration of having very limited options.

Please post us some photos of your tank, we love having a nose :hi:
Pic of tank, Coolies are out, guppy at top and I think capt grumpy is in his cave. :lol:, bit of my reflection in glass, sorry.
We have all been there! I lost a few fish trying to make it work in a tank that was too small, upgrading to a bigger tank was the best decision I made. Gives you many more options for what you can keep and how many. I don't know enough about the fish you've got currently but there may be some incompatible ones, someone else will be able to confirm.
Welcome to TFF... :hi:
We all went through a learning curve...

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