Join Date: Apr 2013
Location: Southern California
Seem like not a nutrient deficiency if you are dosing normal EI. EI should be more than enough + 50%WC/week. If you are dosing potassium-K dry without mixing, when it sink down and touches any leaves it can cause burned pinhole & melts. Old damaged leaf cannot be repairable, trim & discard.
Also, I use to have amano shrimps picking algae or what-not on my hydrocotyle tripartite and causes pinholes & tears.
Culprit might be the big guy in the picture. Keep an eye on this dude.