gmluk gmluk
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  • Posted on: 28/7 20:56
Dying fish #1
Hi, new here but really need some advice. I'll keep it as brief as possible. We started our first tropical tank around the start of April this year. Its 105 litre and we started out with an assortment of fish including zebra danios, neon tetras and a couple of plecos. Problem is, and hands up here, we didn't do our research and the tank was nowhere near cycled when we added the fish. Feel terrible about that. We only realised this after some of those fish and some others that we added afterwards died. We slowly learned what we should have known from the start and cycled the tank, used Seachem products like Matrix in the filter, Prime when doing water changes, Stability to help the process along, and purchased the API master test kit to monitor water levels frequently. We eventually got to the point that the water parameters were fine, zero ammonia and nitrite, and weekly (often more) water changes to reduce the nitrate levels. So although we knew the original fish may not make it (three of the original danios, the plecos and a couple of tetras are still going) we felt confident that we could add more fish slowly but surely. Over a few weeks we added two kissing gouramis, two dwarf gouramis, and four dalmation mollies always making sure the water was ok, and we added them safely, following the all the guidance out there for adding new fish. All seemed fine up until last week, now we've lost the gouramis and one of the mollies. The water parameters are still fine, none of the fish seemed to have a problem with each other, the tank is well oxygenated etc. I know we did wrong at the start but even now everything seems to be right we're still losing fish. I just need some help to try and work out why. Any help much appreciated.
fcmf fcmf
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  • Posted on: 28/7 22:49
Re: Dying fish #2
I'll have to answer more comprehensively tomorrow but two thoughts occur to me:
* what is your water hardness in CaCO3 and German degrees hardness? (Water supplier ought to have details for your postcode on its website.) [Some of your fish are soft-water, some hard-water.]
* fish combinations may not be compatible (eg fast-moving fish stressing sedate fish).

Once you let us know the answer to the first, this will help us get a rounder picture of what might be happening, to be able to offer you better help.
fcmf fcmf
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  • Posted on: 29/7 14:11
Re: Dying fish #3
A few more detailed/further thoughts:
* you seem to have learned a lesson the hard way about the importance of cycling and water maintenance but seem to know what you're doing now which is great;
* NB it's important not to purchase any species of fish until you've done your own research on it - species profiles are available here https://www.fishkeeping.co.uk/modules/ ... resheets.php?cat=Tropical, and more (species profiles, details and up-to-date info) at https://www.seriouslyfish.com/knowledge-base/
* from these species profiles, you'll see that:
*** many of the fish require a larger tank than your 78cm long tank - zebra danios and short-finned mollies (90cm +), plecos (depending on which type you have), kissing gourami (150cm +), etc.
*** kissing gourami in particular become very aggressive if in a confined space or competing with others for the same space;
*** compatibility - zebra danios are fast-swimming, others such as gourami often slow-moving, which can become stressed in the presence of faster swimmers;
*** mollies are hard-water fish, so won't do well if your water is soft; conversely, neon tetras are soft-water fish, so won't do well if your water is hard.

I'd say it's likely that there has been stress in the tank due to a combination of the above, and that has accounted / is accounting for the deaths.
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  • Posted on: 29/7 20:54
Re: Dying fish #4
Thank you for taking the time to reply. Ok so have more information now. I've just tested the water again......

Ammonia 0 ppm
Nitrite 0 ppm
Nitrate 10 ppm (actually slightly lower i think, did a 30% water change at the weekend)
pH 7.2 (same result from both tank water and tap water)

Sorry I don't know what the other measurements for water hardness would be.

Like I said, the fish we had before the tank was ready I expect not to live much longer. It's the ones we've added since I'm confused about. In the last week we've lost the two dwarf gouramis, one of the mollies, and a couple of platies.

We always ask the advice of the staff in the aquatic shop and do look at online advice for mixing fish, a lot of which suggests the combinations we've had shouldn't be a problem.

I just want to find the solution and best combination of fish for our setup without the constant worry of them dying.

Thanks again.
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  • Posted on: 29/7 21:21
Re: Dying fish #5
Sorry, meant to add water temp is bang in the middle of the green of the thermometer at 23 degrees C
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  • Posted on: 30/7 18:37
Re: Dying fish #6
I'll need to be brief, but just a few points:
* the fish that went through the fish-in cycle might still survive, so don't become too disheartened or give up hope just yet;
* previous comment about where you'll find your water hardness figures still applies - this is particularly helpful for choice of future fish;
* previous comments about potential reasons for the various species of fish not having survived or not doing well going forwards still apply - with the addition of platies being hard-water fish, so won't do well if your water is soft (this species hadn't been mentioned before);
* local fish/aquatic shop advice, and online advice, can vary greatly - the links previously provided are reputable resources, though.
Hope that helps for you going forwards, in conjunction with the ongoing monitoring of water quality and additional/larger water changes to address that if/as required. Best of luck.
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  • Posted on: 31/7 23:03
Re: Dying fish #7
Thank you once again for your help. It seems that with the cycling learning curve we neglected to consider the other factors. We'll certainly take a look at the links and generally do more research before adding more suitable fish.