[ShaneSmith]

Well you need to be sure that there is new growth showing deficiency signs my man. K deficiency will be experessed in older leaves, so it will not be as easy as just looking, the older leaves will stay damaged and the holes wont fill in. My suggestion is to mark a leaf somehow that is the last old leaf with damage and watch for holes on the leaves above it.
Once you are sure there is new damage and its not from a fish... i would suggest Zapins little plan. Making a new solution is kind of a waste of time because you can just continue dosing PPS pro and then as things decline again (if they do) then dry dose more K. I doubt you will have to do this very much at all. Exact ratio's are not very important (Not coming from me coming from a PhD in plant Biochemistry).

 

[ShaneSmith]

BTW ray your right you cannot be sure their is a deficiency just by the holes, but deficiency signs are very well documented so it is a very good indicator. I'm not sure how long you take your K measurements but testing water is probably a poor way of deciding you have K deficiency. Plants have very large storage capacity for most major nutrients, enough to grow without taking them out of solution for a very long time... I like where your mind is at though. Also check for magnesium, just because GH is in order does not mean Mg is. Marginal chlorosis is K deficiency usually white inervein chlorosis is Mg. Holes could be from K, Mg, or maybe PO4 depends a lot on species reaction.

 

[ShaneSmith]

Any yellowing? Holes without yellowing make me think fish or snail damage is to blame

 

[ShaneSmith]

i doubt this is nutritional deficiency. Get rid of the critters doing the damage.

 

[ShaneSmith]

Get a dwarf puffer, they eat snails and are great fish. Most people have no problems with the dwarf ones and plants.

 

[ShaneSmith]

That may keep the snail popultion down but it wont eliminate them...