Lights and pinholes in my plants.

[khanha3]

Hi, I started my planted tank back in July. I had some Hygros and other plants in it. For the first 2 months they grew without a problem dosing API leaf zone. Recently the next 2 months (sept- oct) hygros and amazon swords started to have pin holes form on their leaves.

After some research pinholes are caused from lack of potassium.
Aren't nutrient deficiencies for higher lighted tanks?

I have a 20w pink florescent bulb over a 29g tank that's probably used for 3 years, 15 years ago....(got a hand me down tank from my dad)

 

[FrostyNYC]

Plants growing under low light still need nutrients to grow and also to maintain their existing leaves. Perhaps increase your dosage? Note that Leaf zone contains some micronutrients and potassium, but no nitrate or phosophorus (the other building blocks for plants). I've also had pinholes develop in my plants due to lack of CO2.

Something else to consider: Is it possible that you have snails or fish snacking on the plants?

 

[khanha3]

Hmm.. no co2, I have a small colony of feeder guppies (8 adults 5 juvies), 20 cherry shrimp, 6 ghost shrimp, trumpet snails and ramshorn.

2 weeks ago I changed substrate from sand, to 50/50 sand and fluorite black sand.

I'll up my dose to twice a week instead of just once a week during WC.

Its just weird the hygros were growing real tall and good for first 2 months ~20", all of a sudden all the plants got pinholes which lead to whole leaves dying off. Even after trimming, pinholes still appeared.

Thanks for your input =)

 

[coach_z]

if i were you i would really replace the bulb....although they will emit light they are only good for so long. I would also find a way to get a comprehensive range of ferts into your tank so that you arent missing anything....that should be all you need for that tank.