Mmiller2001

https://aquariumscience.org/index.php/10-2-4-epistylis/

I only used the one o-ring. I can see how that's worded funny. I don't think I read their directions now that I think about it. I do purchase and replace the o-ring every time I refill the tank.

I would just get one from wherever you fill the tank.

https://www.2hraquarist.com/blogs/ph-kh-gh-tds/is-low-ph-in-tanks-due-to-aquasoils-softwater-a-concern https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489657/

Looks like you are low on CO2 FYI. Keep an eye on them. If any other fish starts flashing, it's most likely flukes.

What is the TDS of the tank? Are all your fish soft water fish? I would look at the TDS of the tank and the TDS of your source water. If there's a large difference, that could cause some irritation. I would expect to see flashing after a water change though. I had a very resistant strain of flukes. I would treat and it would be fine for some weeks and then the flashing would start all over again. Finally, I had to dose prazi Pro for 5 weeks straight and Paracleanse for another 2 weeks to finally cure the problem.

CO2 and fertilizer do not cause flashing. You need to maintain 20 to 30ppm CO2 or you are going to have problems. I would look at other sources for the flashing. For a while, I was dosing 30ppm Nitrates, resulting in 60+ nitrates with no I'm ill effect. Think of NO3 from fertilizer as different from NO3 from fish.

They will develop roots over time. 2 inches would be fine. Just enough to hold it in place.

Helps expel any internal parasites.

I would plant it, looks better that way. Pretty easy plant to take care of. You can cut the tops off and plant those if you want to propagate it.

Looks like Camallanus.

That's moneywort.

My LFS are filthy. I too have to deal with big box stores. After that, I use aquabid.

Did you follow up treatment for Camallanus worms? Usually, a 2 week follow treatment is recommended. And what did you treat the worms with? The flashing is most likely Flukes. I would treat with Fritz Paracleanse or API General Cure. Another option is using PraziPro. But you have to follow up in several weeks to kill the hatched eggs.

It's the same thing as Bacopa caroliniana.

I would not use them because of the pollution they may carry.

https://greenleafaquariums.com/products/potassium-sulfate-k2so4-1lb-bag.html This will last forever.

GH is made up of Ca and Mg. KH is made up of carbonates and bicarbonates Seachem Equilibrium will increase GH and has some potassium and iron it. To raise KH, Seachem Akline buffer would work well and is easy to dose.

Check Petsmart, I have found API General cure there.

This! Pick what looks best to you. If cost is an issue, look at Black Diamond Blasting Sand.

I would not trust those. Where do you live?

Most hobbyist level testing has very low resolution; I have to say they are all low accuracy. The amount of money you would have to spend to increase accuracy would be ridiculous. From my experience, and reading, trust dosing numbers over testing numbers. When I test Nitrates, I'm only testing for it's presence. Same with Ammonia and Nitrite.

If he's not eating, he's dying. I would hit him full med trio. If you don't have those meds on hand, I would use Fritz Paracleanse/API General Cure and start today!

Have you treated with any meds at all?