Recovering Tanks From Potential Toxicity

Hello all! I have a rather specific situation I'm hoping some of you might know something about.

Here's the story: over the course of many months, I have brought bettas home to my filtered, cycled, heated, planted, disease-free 10 gallon tanks that receive weekly 30% water changes and they were fed good carnivore foods. They would color up and become active and vibrant for a while, then slowly begin to lose energy. They would just wither and die without any symptoms of typical sicknesses. It came to my attention yesterday that the floating log ornaments that I have (2 in each tank for the past year, my bettas love them) almost certainly have been leeching paint into the water long term. As no other disease or sickness can be identified in all of the bettas that have died in my tanks, this is the culprit right now.

I have removed the logs and thrown them away.

I have two 10 gallon tanks, one is empty except for Nerite snails because its fish inhabitant died yesterday (RIP Sully), and the other still has a betta and Nerite snails. The betta that is still living doesn't look as bad as the one who just died, but he's not looking great either.

I am about to do my water changes on both tanks and run to an aquarium store today. Here are my questions:

- Now that the source of the paint has been removed from the tanks, I should be doing a larger water change than normal, correct?

- Is my filter media contaminated by this? Should I be switching it out completely and re-cycling my tanks, or will giving it a good rinse in dechlorinated water be enough? I use TSS to cycle my tanks so re-cycling is no inconvenience.

- How long should I wait to put a new fish in my empty 10 gallon? Is a big water change and good cleaning enough, or does some time have to pass?

- Will the betta I still have make it? He looks okay at best right now and I'm hoping his condition improves now that the source of the poison is out of his tank. I will be doing a larger water change than normal today. Is this kind of damage permanent to fish?

- Is there anything that I can buy at the store today that will help with any facet of this issue?


Thanks to anyone who responds! It's been a long time of disheartening confusion so I'm hoping that I've finally found what's been quietly killing my fish

 

You would have to know what the actual chemical responsible was to answer your questions. The symptoms combined with the suspect paint have me thinking lead contamination. I wonder if your local water company or medical authority would be able to test for that?

 

Oh yikes

Well I'll start there, I hadn't considered lead.

Would lead kill my snails? They're alive through all this and I wonder if that serves as any indicator.

EDIT: I'm doing some research and looks like some water conditioners detoxify heavy metals like lead at normal concentrations. I use Prime and it says it does detoxify heavy metals.

I'm gonna keep reading, but this sounds like frequent water changes with my conditioner might help this problem, if that's what it is.

 

I would add a new carbon pouch to your filter. Might not help much, but won't hurt.

 

the logs were ZooMed betta logs right? I would try contacting the company and asking what material the log was and what was in the paint. Or maybe go to Amazon to see if there's any info in the description or to see if anyone else has asked the same question.

 

They were ZooMed, yeah. The general consensus online is that many of people who experienced this kind of thing contacted the company, who said everything they use to make them is non-toxic but that's all. Idk if I'll get any more info than them but it might be worth a shot.