OK, so I may be onto something with this dratted high pH.
Have been reading and reading.
Have done repeated water changes, removed the resin root decoration, wracked my brains... Removing the root has made no difference whatsoever, so it can go back.
Every water change causes a lovely drop in pH, but within 24 hours, it is back up to 7.4-7.6
Then last night I came across an excellent article on how to naturally raise or adjust the pH of your tank.
All the usual suspects were mentioned, from catappa (IAL leaves), driftwood, peat in the filter, removing the root cause of the problem, etc. etc.
And then a short little section about adjusting the oxygenation of the water.
Apparently, high aeration will push the pH up a bit, and low aeration will increase the acidity - which must be one of the reasons why slow moving waters are often more acidic than fast moving ones.
And the penny dropped! Just before we went away for our week's hol, I turned the flow up on Valentine's outsize HOB filter, because I knew he wouldn't be getting the usual frequent water changes, and I wanted to increase the filtration.
Now this is an outsize filter anyway (suitable for a 70+ litre tank, in a 22litre tank) and I switched it up to max.
That is a heck of a lot of aeration.
Anyway, I didn't turn it back down when I got home, on account of Val's death and me wanting to keep the filtration high.
But I have now turned it right down and will keep checking the pH to see what happens.
To be honest, I am now thinking that IF it was the extra aeration pushing the pH up, then it wasn't likely to be a contributing factor in Val's death. That was probably the excess food. Either him eating too much, or the water turning briefly toxic.
In other news, the yellow dwarf shrimp are a DELIGHT. They are happy, busy, and soooo cute. I cannot believe I have not had them before. There are 10 of them in the 22 litre (enough to maybe breed in future) and there is usually around 5 or 6 in sight at any time. Busy, busy, busy. They have even brought the amano out of hiding, and he is now part of the group. The second amano is still playing hard to get, but we shall see if that changes in time.
: (Kham) mature setup; betta, purple rasboras, amano and wood shrimp. Heavily planted.
22litre cube tank
: (Tagawa); betta, 2 amano, yellow dwarf shrimp. Heavily planted.
57litre cube tank
: (No Name); betta, ember tetras, 2 amano, 1 nerite, 1 assassin, doing his thing. Heavily planted.
; honey gourami, cherry barbs, green neons, kuhli loaches, otocinclus, nerites, pond snails, amano. Heavily planted.
Last edited by bluesamphire; 06-28-2019 at 02:47 AM.