Identifying causes: bacterial illness in corydoras?

[megwattscreative]

Hi all, wondering if the bright minds of UKAPS can help me narrow down the causes of some bacterial illness issues in my first tank. It's all documented in my journal if you'd like more detail.

I had some bacterial issues in my tank a few months ago after introducing new fish without quarantining. The fin rot and white spot cleared up after adding more filtration, more plants and a treatment with ESHA Exit and ESHA 2000. However, some corydoras still showed signs of bacterial illness months later (symptoms included white pallor on scales, sand sticking to fins/barbells, one Cory not regrowing fins). The most effected cory eventually died on day 2 of a second retreatment with Esha 2000, however it's a week on now and the rest all seem fully recovered.

This is what I've changed to (theoretically) encourage recovery:
-mass pruning of dead/melting plants (floating, emergent, submerged)

• standard softwater dose of Esha 2000
• increasing filter turnover
• repositioning hardscape and filters to increase surface disturbance
• 50% water changes without adding my usual ferts (solufeed 2:4:1, chelated iron)
• reducing feeding regimen to prevent build up of excess food (I know overfeeding just because they're begging is silly, but I grew up with @dw1305's truly demonic cat.. I'm unlearning the marginally safer path of least resistance)
• vacuuming up any excess food (and consequently some leaf litter mulm/snail droppings)
• taking out any extremely elderly magnolia/oak/beech leaves (there were a LOT in there)
• removing some dripwall tubing that was serving no purpose - thank you @ScareCrow for the idea.

I am going to monitor plant growth (hooray for the duckweed index) before adding ferts back, however I am going to need to add ferts eventually.

I'd also like to go back to adding tannins with each water change. Here are my queries:

1. What do you think helped most/made the biggest change to bacteria?
2. Can you see any issues with lots of old/almost fully decaying leaves?
3. Could the ferts have contributed to the water quality in terms of bacteria?
4. Any thoughts on initial causes?

Looking forward, I have some questions:
5. when you add tannins, do you remove old leaves?
6. Do the leaves you add have to be totally brown and dry? I have been adding fallen leaves in clumps from an oak tree that have been blown off in storms, and some off them are still a little green.
7. Shall I keep up 50% weekly water changes? I usually do a 30% change, however I think 50% may be more reliable.
8. Shall I buy a new air pump for the matten filter? I'm currently using a secondhand eheim 200, however I'm pretty sure one of the tube outputs has failed which may have contributed to the decrease in water quality. It was just attached to an airstone floating in the back of the mattenfilter. I'm not fully clear on how airpumps work, or how to get the best out of mine!
9. Would treating planaria help? I've bought a trap, but am hesitant to use it right now and add more food to the system.

Thank you for any advice or thoughts - it's all very welcome. I'd love to learn from this and avoid any future issues.

 

[dw1305]

Hi all,

but I grew up with @dw1305's truly demonic cat..

That is no way to <"talk about her">.

Can you see any issues with lots of old/almost fully decaying leaves?

No, I think they are OK. They don't have the capacity to be <"very polluting"> have a look at <"All the leaves are brown… — Seriously Fish">.

Do the leaves you add have to be totally brown and dry?

Yes, they need to be shed naturally, or the plant won't have withdrawn the protein (in chlorophyll) and carbohydrates from them.

I'm not fully clear on how airpumps work, or how to get the best out of mine!

Have a look at "Czech Airlifters" <"Air lift pump">. <"EnvoBeeShrimp"> sells them in the UK (<"Swiss Tropicals in the States">, and most places <"in Europe">).

cheers Darrel

 

[megwattscreative]

Thanks dad, I'm very excited to see her majesty however I think you know exactly what I mean 😅
I think I've been going wrong with adding green leaves, so I will edit accordingly.

 

[Bradders]

1. What do you think helped most/made the biggest change to bacteria?
4. Any thoughts on initial causes?
7. Shall I keep up 50% weekly water changes? I usually do a 30% change, however I think 50% may be more reliable.
8. Shall I buy a new air pump for the matten filter? I'm currently using a secondhand eheim 200, however I'm pretty sure one of the tube outputs has failed which may have contributed to the decrease in water quality. It was just attached to an airstone floating in the back of the mattenfilter. I'm not fully clear on how airpumps work, or how to get the best out of mine!

I can give you my thoughts / 2-cents - but in reality, who knows for sure?! 🙂

As a guy only learning 'the art of plants', I am still in the technology filtration camp. Not necessarily for the nitrogen cycle, but having large amounts of biomedia surface area and good flow to (try and) capture/process as many free-floating pathogens as possible, maximizing the fishes immune system to deal with as close to 'one' issue as possible. We established that your filtration was initially going via the path of least resistance, so I think that bypass would have contributed to your problem. I also think disease its harder to get rid of, then it is to prevent. So under-performing filtration and an outbreak is going to aid spreading and create recovery challenges.

Initial causes could be one thing, or a mixture. Bacteria build-up in mulm, infected new fish, bypass-filtration etc. I think you are asking this question in the guise of how to prevent it happening again? My advise would be to keep doing what you are doing and let the fish tell you. For example, if you complete the treatment and all fish return to health and stay healthy (without medication) then you know things are pretty good. Again, being the tech guy, I would maximize that wonderful matten filter, ensure there is no chance of bypass and make sure you understand/monitor the turnover rate. What you are looking for now is a long period of health without intervention.

I am not experienced with mattenfilters, but after your issues I started to look at them!! In the configuration below (its from a supplier product but the diagram was good!) you can see that there is a tube with an airline which displaces the water, which pulls new water through the sponge and dispels that water out of the top. Now, some clever people have removed the airlines/airstones and replaced with powerheads to turbo charge the flow! I guess its possible to consider that as an upgrade option? (Assuming that you not happy with your current configuration?)

 

[megwattscreative]

Hi bradders, thanks for all your help!! You've been wonderful.

removed the airlines/airstones and replaced with powerheads to turbo charge the flow

I actually ended up cobbling something similar-ish together: because of the positioning of the hardscape, the matten filter was really only pumping water out into one side of the tank. i maxed out the flow on the air pump, whilst also adding this pump (API flow 400) to the other side of the tank (its small, so easily positioned within the mattenfilter). I added a short length of tubing so that the water is dispersed over the foam like a Czech airlift. This theoretically upped the water turnover 2x, however due to the malfunctioning airpump I think it equates to about 4x.

I think you are asking this question in the guise of how to prevent it happening again?

I am! But I also want to hear people's opinions re most likely causes of bacterial illness. Its useful info for beginners like me, in my opinion. I think filtration was probably my key issue, however overfeeding cant have helped!

 

[Bradders]

But I also want to hear people's opinions re most likely causes of bacterial illness. Its useful info for beginners like me, in my opinion.

I think the causes of a bacterial diseases can be many, which complicates things. I have read story's about bought and sick fish introducing nasty issues into an aquarium, and a mature and healthy aquarium suddenly springing up with a disease from nowhere - without any recent introduction of new fish or plants. I have pondered over this quite a bit, and have opted to make sure I maximize the health of an aquarium as I assume a disease is always just around the corner.

I have Cardinal Tetras in my aquarium, which are meant to be quite sensitive by all accounts. They come from waters which are low-bacteria and therefore their immune system is not as strong as some other fish. So the fact I have kept them alive for 18 months with not one loss gives me some comfort that the environment is reasonably healthy. But I have had other fish die (mainly livebearers like guppy's) in that 18 month period - and mainly from things that I just could not understand what happened. Could be anything. However, a good example (if you remember) is my Platy that suddenly got fin-rot. I am confident that was caused by the bullying he gets, the stress that occurred and subsequent health issues. So a slightly weakened fish and suddenly all hell breaks loose - but the (allegedly) sensitive Cardinals just keep going and going. So even in an aquarium which (anecdotally) is healthy, there is still enough pathogens waiting to find the weakest fish to pick on. (NOTE: He is slowly recovering and growing new fins, but have had to change the tank so there was more hiding spots!)