Yes, yamatoes only eat leaves which are dying or dead leave, they won't touch the healthy ones, the fact that your banana plants have holes indicates your tank is lack of something. My advice is still your CO2, I would actually get a cheap Mid Range pH drop test, mine only costs like RM15, they are quite consistent unlike the your pH pen. pH pens need calibration and not accurate at all. If yoy still want to use your pH pen, I would recommend you to target a pH of 6.5 from your pen. Any other plant problems besides this? and what ferts are you using?

I am current using the test kit from JBL for both pH & kH, not using pH pen.
pH is drop 4 drops and match the colour chart. kH is drop until colour turns yellow.

Or perhaps I see the colour wrongly on the pH chart... the 7.0 and 6.5 colour looks kinda the same... the above 7 colour looks much darker so I can recognise that one...

Correctly me if I am wrong, I tot lack on CO2 only slow down the plant growth rathar than the leaves breaking up... some of these leaves are not old leaves...

Other plant leaves does not break up. Happens for both surface and submerge leaves..

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Don't use JBL lar...their PH range is kinda far. 0.5 distance is kinda big different. use the one with 0.2 distance.

JBL PH tester just caused me to kill 2 of my wild caught altum. damn...

ok ok any recommendations on the brand that test for a more accurate ph & kh ??

Thanks

Stanley

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you know what I'm using? A cheap Wardley brand Mid Range pH tester I find it to be very consistent & accurate. Just put 2 drops of it in 5ml of water, then give it a shake, the colour comes out nicely