Perrow

Googled it and saw eerily similar pictures on another forum, they said hole-in-the-head and suggested water changes and vitamins. Anything more I can do? They also suggested methylene blue dips, I have MB and could do that. They might be slightly "lightly" fed and will up the feeding with some different frozen foods I have.

So saw these just now, any idea? There's another Angel with similar but not a pronounced "spikes" also on the forehead. Normal water parameters, unheated. Community tank, no other fish (that I've seen show any signs).

I pour some of the culture into another container. I place a funnel into the flask I keep my culture in and a coffee filter in the funnel. Pour the culture back into the flask through the filter. When all vinegar has filtered through I "wash" the filter in some tank or tap water (we have low chlorine and not much else to worry about in our water). Then just pour the water into one or more tanks. I typically reuse the filter many times. Oh, and I "split" the filters so I have a continuous piece of filter paper with no seam, the seams (on my filters at least) have bigger holes that does'n matter when you make coffee but the vinegar flows right through.

Helped my daughter catch up with some schoolwork and it talked about PH, so we dipped a stick in one of the tanks and looked at the PH (7.5, a little higher than I expeced but nothing special). But looking at the strip I see that the nitrite reading is definately not zero, more like half way to 0.5, so next thing I started doing water changes. The tank we measured (40G) houses ~25 Angel fry and ~80 Bristlenose fry and some Guppies, I might have to up my water change schedule on that one and hopefully get rid of a bunch of those fishes soon.

Decapsulated Artemia eggs helped me raise Angelfish fry and Pygmy Corys.

The hose to do water changes must be my best buy. An alarm to notify me when the tank is about to overflow would be if I'd found one. My body is ten years younger than yours but my mind is the same age. I recently spend ~€70 on a humidity sensor device after flooding one tank. Took two days to get the humidity down to acceptable levels. If you ask my spouse she'll tell you that's my best buy 😁

Not coming in with any tips on your canister Ruud, but your tetras are most likely Cardinal Tetras rather than Neon Tetras.

Mine laid their eggs all over the tank, on Guppy Grass, stem plants, Crypts and the glass. The eggs are quite easy to roll off the surface they're on and I just transferred to a small container where I added anti fungal (methylene blue) and an air stone. When they hatched I moved them (actually pipette'ed them) them to a larger container with an air driven filter, some plants and a little sand. Had most success when I fed them decapsulated brine shrimp eggs.

My guess would have been green hair algae.

Interesting, are the active ingredients the same or equivalent? I'm from Sweden and I think I can get all those Esha products.