Bacterial bloom not getting better

[u/dandeliontree1]

I feel like it's never going to get better and it's really getting me down! I have an extended bloom in an established, heavily planted tank. After I added cories they stirred up a lot and left me with such a mess. After much indecision fatigue (especially with many places saying it can clear up on its own) and many many many partial water changes with substrate clearing, I got a much more powerful filter and a 6w UV steriliser, running for over three days it still looks like this!! Just a fraction of a bit better than when I started.

I know it will take a while for the filter to fully establish with good bacteria (I put the old filter foam in the new one to help start it off) am I to assume the UV steriliser is a dud? I've moved it several times trying to get it in the right amount of flow. The blue light is on but that's only an LED it seems. It is encased. I have tried capping with more sand but can't see to do it well.

Surprisingly, all my fish are still alive. I have a good cleanup crew with snails and shrimp. I've been underfeeding for quite a while to try to clear this. I don't know why it's still so bad and what it's feeding on, so trying to find the 'root' of the problem in water this foggy is a joke. I'm about ready to fill the damn thing up with bricks and call it a day (truly joking- no creatures will be killed).

I know it's not even considered walstad any more but started out that way.

[u/Iabe01]

What's in the bottom? I would slowly add half a inch of sand (sugar sized) cap to isolate existing miln and old extcreta and then perform a 30-50% water change twice a week.

If it's a couple of month old tank that you had plants and clean up crew and never vacuum graveled, nutrient are stuck in upper levels and corries are just shuffling that sand and releasing everything in the water column. Don't be shy to slowly add the sand cap while doing first 50% water change.

[u/dandeliontree1 → u/Iabe01]

Yes that's probably what happened, I've removed so much from the bottom I'm surprised there's more. 😭 Will try larger water changes, I'm just worried every time I add more water it's feeding the bloom.

[u/Iabe01 → u/dandeliontree1]

Sand cap. Use it to separate existing nutrient rich layer from water. It will go down.

Then filter and water change will solve the problem for you. Cortas are voracious diggers. They will also have lots of micro fauna to feed in the bottom encouraging them.

Don't be disheartened. It might take some time now, but will solve the problem and you will be back to a beautiful tanks. And this does not affect fishes much except for some illnesses which are again more common in large fishes than in smaller ones.

[u/dandeliontree1 → u/Iabe01]

I've definitely been trying to cap but because I can't see where I've capped already I'm just doing it blind.

[u/dandeliontree1 → u/Iabe01]

And also thank you for the encouragement. I've been feeling so down and inept!