All but one loaches have died... What now?

Hi everyone,


I got loaches to add to my community tank (4 guppies 6 Neon tetras) about six weeks ago. I saw them a lot at first, then less and less. I last saw my second to last loaches two weeks ago, and have only seen my last loach since then (he comes out regularly, big fan of food time!). I've been increasingly worried about them and waited in the dark until 1am to spot loaches, but I only saw one. Finally this morning I found the courage to check inside a hollow rock decoration I had and my worst fear came true, it was full of dead, decomposing loaches. It was terrible. I am still devastated and can't get the awful smell out of my head . I don't know if they got stuck in the rock and died, or went into the rock to die but I'm absolutely devastated... My question is, what do I do now? I did a big water change (70%) and threw out the hollow decorations and bought a small rock cave for my last loach to hide in if he wants (smaller decoration with bigger holes meant to be swam through). I should also mention I think he was the only loach too fat to fit inside the hollow rock I used to have. I'm worried the lights in my tank were too bright and might have driven the loaches to hide inside during the day... I'm keeping the lights off for now and planning on buying dimmer lights. I should also mention I do 10% water changes every three days and test the water each time. There was a small nitrate spike 2-3 weeks ago at 50-60ppm, I'm wondering if that contributed?

What should I do to keep my last loach happy and healthy? I love him so much, I don't want to lose him... I know loaches prefer company but my quarantine tank is currently occupied by guppy fry (for a different tank) and I'm honestly scared to repeat this tragedy

 

Welcome to Fishlore.

Sorry for your loss.

The first question is your aquarium cycled? What are the parameters?

How large is the aquarium?

What fish are in there?

What water are you using, well, city, RO/DI? How are you treating it?

 

Thanks Thunder

Aquarium is cycled, I did I quick start with bacteria for a week with Seachem Stability Water Conditioner. I am wondering if such a big water change will mess up the cycle? I've never done that big of a change before, and I also had to replace the filter cartridge since it got clogged up with bits

Would it hurt fish to add more bacteria and treat it like a new tank? I know loaches are sensitive little guys and I imagine my surviving loach is probably pretty stressed from the big water change and removing the rock

Parameters:
0 nitrites
5ppm nitrates
0 ammonia
0 chlorine
Soft water
PH around 7.5
Temp at 77 degrees (previously 73-76 but I upgraded my tank heater to keep it warmer and more steady two weeks ago)

20 gallon tank with
- 4 guppies, all male
- 6 Neon tetras
- 1 Kuhli loach

I treat the water with Prime de-chlorinator/ de chloramine. (I don't know which is used to treat my water, I live in a city - no well)

I change the water a lot because I use a gravel vac to suck up any uneaten food... The tetras don't like seeing a net and I don't have the patience to use a spoon lol

Also I'm sorry I have no idea what Ro/Di stand for, I am a bit of a noob

 

Rodi is reverse osmosis somthing. As in, special water stripped of bacteria for sensitive fish, but you need to add vitamins to it.

No, you should not need to add more bacteria, your tank is still cycled.

You should try not to add more food then the fish can eat. In fact, you should add less then the fish can eat, if you have that much leftover that you have to remove it every time, you are over feeding, and you are dirtying the water even if you remove solids.

Large water changes should be ok to do without killing the cycle. Large water changes can be stressful to the fish for many reasons, "water chemistry and temp..." so I don't usually go past 50% but I do on occasion. Changing the filter cartridge is a risk, but it is not as bad as I used to think. There are nitrifying bacteria all over the filter, and all over the tank. I still recommend keeping extra filter media in the filter and never rinsing the cartridge in tap water, but it takes a lot longer for chlorine to work than I use to think.
so, you have one loach. I understand your trauma, but you might want to try again to keep him in a school, they are social animals. Consider larger, open, smoother hideouts like PVC pipes, terracotta Vases, sideways glass vases.

 

How are you testing the water?

RO/DI water is water that has been stripped of everything, minerals, chemicals etc. You then remineralize the water. This must be done to prevent a pH crash which is fatal. Many of us have installed these systems to give compleat control over the water. The systems range from simple under sink units to rather involved ones like the one I built
My RO/DI System Setup | Reverse Osmosis - Deionization Forum | 367737

While the nitrifying bacteria is on all surfaces of a well established aquarium being opportunistic critters they mass where the most food can found which is in the filter As the food breaks down it produces ammonia that is converted to nitrite which is then converted to nitrate. Nitrate is then removed through water changes and/or live plants. By changing out the filter medium for new you effectively removed your bacteria colony. Next time just swish it in tank water at a water change.

Adding more bacteria will not hurt the fish and I would advise it at this point.

Noroomforshoe is correct that loaches need to be in groups, and makes other good points.

As for filtration, any of our aquariums 20 gallons and up have two filters (we run 10 to 150 gallon aquariums). This does several things: 1. makes it easer to achieve the 10X the water column in GPH filtration that I keep. 2. if something goes wrong with one you still have filtration. 3. You can then preform maintenance on a rotation with no risk to the cycle.

Feeding: if you are feeding to the point that there is food not eaten after several minutes, back down on the food. Fish are cold blooded and need far less food than many people think.

Neons are happier in water in the lower 70's.

It is entirely possible the decoration trapped them. As for lighting do you have live plants? (whole other discussion) As long as there are places for them to hide it should not be an issue.

Keep us posted,

Best wishes.

EDIT: Keep an eye on the guppies, neons are known as nippers of long flowing fins. Does not always happen but when it does it becomes a real problem ie. male bettas.

 

Thank you both for some very good points and advice!!

Firstly, I will stop overfeeding my fish!

I've been testing my water with test strips, but I've heard a lot about the liquid test and how those can be more reliable so I ordered one yesterday.

As for filters, I will go get some extra filter media to add to the tank (a great idea, thank you Noroomforshoe) and also add a sponge filter too. I think that would be good for when I need to change the cartridge and a good source of oxygen. Also I am ashamed to admit I have been rinsing the cartridge in tap water when I change it, I won't do that again!

I will also turn down the water a degree or two for my tetras! The tetras have never shown any interest or aggression towards the guppies but I'll keep an eye on them just in case. They're little angels tho

I do have live plants, some Java moss (although I keep sucking it up in the gravel vac by accident), a small Java fern, and two other plants I've had for a while and don't remember what they are off the top of my head... I think they're low light plants too.I also bought some fake grass yesterday for my last loach and he seems to love it, he spent all day yesterday hiding in the grasses in different places. He seems to be doing ok so far.

I'll look into getting a terracotta vase, that's a great idea!

I will also go get my last loach some loach friends so as soon as the quarantine tank frees. I don't want my poor little bud to be lonely, I imagine he's already been alone for nearly two weeks now

Thank you both for great advice