[Higher Thinking]

So I know that pinholes are a result of potassium deficiency so I'm most certain this is the case. It starts as pinholes in the center of the leave and then progresses outward until the leave eventually falls off. The deterioration is occurring in old growth leaves. I already dose 1/4 tsp three times weekly of K2SO4 in addition to 1/2 tsp of KNO3 and 1/4 tsp of KH2PO4. The general guidelines for EI dosing don't even call for the additional K2SO4 unless their is an overabundance of K usage. Do I just need to go even higher with the K? Just want to get some confirmation before I start pumping out more. I also realized that the K2SO4 never dissolves all the way in the cup as there is still some crystals when it enters the water. Does that not eventually dissolve?

The tank is a 75 gallon, EI dosing, CO2, quad T5HO (single reflector) hanging 6 inches above the tank for 10 hour photo period.

 

[Dempsey]

Too much light and not enough CO2. That's what happens. Happened to me before. Countless others also.

Raise the lights to about 12". So how that goes for a week or two. Then try turning your CO2 up a tad. Little by little. Day by day or even every other day. Very very slowly...

 

[Higher Thinking]

Too much light and not enough CO2. That's what happens. Happened to me before. Countless others also.

Raise the lights to about 12". So how that goes for a week or two. Then try turning your CO2 up a tad. Little by little. Day by day or even every other day. Very very slowly...

Alright I'll give that a shot. I have quite a bit of CO2 going in as I drop the pH over a point and the drop checker is always yellowish.

 

[Dempsey]

Alright I'll give that a shot. I have quite a bit of CO2 going in as I drop the pH over a point and the drop checker is always yellowish.

Start with raising your light. This will reduce the demand for CO2. That is always the easiest.

It is alway easy to cure a fert deficiency. Just add more.

CO2 is more tricky as we all know. Too much and we kill our fishes. Too little and we get deficiencies that we all assume are this or that...

Too much light and not enough CO2 or any other fert, is asking for trouble. Unless Pea Soup is your goal.:hihi:

Reduce the demand of everything by raising the lights. This will make things much more manageable.

I have 4 T5HO's 15" over my 75g. This seems to be my "sweet spot".