Corydoras sick again

[Naughts]

Anyways, what can I change now to avoid this in the future?
I purchased 15 in October last year, and I have only 10 of them now. Sure, the food is a problem

I will change the diet first and what, wait two three months to see any changes, like them growing up and being fuller?
Or do I also change the sand for a more suitable one, in case this is the issue, as I understand PFS is not good for them at all.

Today or tomorrow I will clean the filter anyways and do another water change. Apart of losing this corydoras, I also lost almost all of the otocinclus. Granted I only have had them for 3,5 months, but out of 10 I had I now only have 3?! I assume the spirulina tablet is also not good, but damn they eat everything I put in there, I have blanched vegetables, greens, soaked leaves with slime coat
What has happened, could it be the source of the fish, maybe they were older (I lost trust in the seller, who knows where and how he got them)? I have so much algae and I assumed all was going well, they had round bellies and were real good. I wonder if I should get another batch from different seller and try again, or if I should just give up.
I read all about repashy and home made otocinclus foods and spirulinas and I ordered also better spirulina wafers. But I am so sad now

It may be difficult to get healthier specimens if the supplier is shared by all of your lfs, but if you can get better stock this may be wise for cories.

My personal opinion for the otos would be don't keep buying them. This is what I have decided to do. They often don't do well in our tanks and as they are wild caught we could deplete wild populations in just a few short years.

 

[Beastije]

BTW have you noticed, in here, in my other forum everyone has cories that are dying or sick. Must be something in the "air".

Anyways, for my corydoras, I decided to overfeed the a little. I bought both fluval bug bites and omega shrimp pellets. Will feed one (type, not one pellet) in the morning, one in the afternoon and alternate half a cube of a frozen cyclops or daphnia every three days. I will also clean the bottom of the tank every 4 days, but not do a major water change, 10% tops. I have read and others agreed that corydoras dont handle large water change ( well, parameter change) and for many users, corydoras became sick/died after a (larger) water change done recently. Could be the beginning of colder water in some countries or people having more time for their tanks now that summer is over and people started poking in the tanks way more...

 

[Colin_T]

I will also clean the bottom of the tank every 4 days, but not do a major water change, 10% tops. I have read and others agreed that corydoras dont handle large water change ( well, parameter change) and for many users, corydoras became sick/died after a (larger) water change done recently.

Corydoras are fine with big water changes as long as the new water has a similar chemistry (pH, GH & KG) to the tank, and as long as the new water is free of chlorine/ chloramine before it's added to the tank.

I used to do 70-90% water changes on my tanks and the Cories were fine. In fact most commercial breeders do massive daily water changes with slightly cooler water to get Corydoras to breed.

If fish are dying after water changes, there is something in the new water causing the problem, usually chlorine or chloramine.

 

[Beastije]

I made a video and posted it on youtube where my corydoras can be seen, can I paste it here so you can check if they dont look as thin and maybe look healthier or just to check them out?
Is that even allowed here to post videos from youtube?
Thanks

 

[Byron]

I made a video and posted it on youtube where my corydoras can be seen, can I paste it here so you can check if they dont look as thin and maybe look healthier or just to check them out?
Is that even allowed here to post videos from youtube?
Thanks

This is the only way to upload videos. Post the link to the YouTube video.

 

[Beastije]

I made two but close together, so basically a one
Thanks for feedback

 

[Byron]

The otos obviously like the green peas, but you should crush the peas so they can get at them, breaking through the outer skin is difficult. Cories will not eat peas, they cannot properly digest the vegetable matter. Make sure the cories get bug bites and/or shrimp pellets, frozen daphnia, or shrimp.

 

[Beastije]

I did boil them and strip the outer layer, I thought it was enough, but will crush them a bit in the future.
I was not feeding the corydoras, but the tylomelania, since they need varied diet in order to not eat my plants cories are just so curious and try to eat everything.
I distracted them with bug bites not long after that.
Btw the M sized bug bites are consumed by my hatchetfish too, if they notice them before the ember tetras sink them down.

Do the corydoras look ok, not thin and healthy?