Holes in my swords...

I'm running a 120 gallon with only 2 X 96watts of 6700K PC AH supply lights with individual reflectors. CO2 injection via an old "power reactor" using a Rio 100 powerhead upside down to dissolve the bubbles.

I'm adding 15ppm N, 15ppm K , and 1ppm PO4, .5ppm Fe using CSM+B 3Xweeekly
I'm only adding ~10ppm of MgSO4 once a week.

I just did GH and KH tests with my crappy test it:

GH = 8
KH = 4

I just started adding Excel to get rid of some algae I have, but I don't understand why I have holes in my swords. The older leaves have them but the leaves that are just coming in are fine. Does a K deficiency affect the older leaves first? Another thing the snails in my tank are completely white? Is this due to a Ca deficiency in the water?

I've just added 15ppm more K tonight thinking that is the cause. Would it also be wise to add some GH booster (which I don't have ).

Should I increase my nutrient levels to full EI? I know it won't hurt, but I want to understand the problem a little better.

Thanks,
Creighton

 

Okay. That makes sense.

What would be the best option for CO2? I like the idea of having a needle wheel pump that you posted a link to earlier, but I'd have to have the pump run out of the water. Or could I just use a nice powerhead with a needle wheel impeller to chop up the bubbles, but not many powerheads are big enough for a 120 and T-Valves on CO2 have been un-reliable for me in past experiences. I don't have much money to spend though.

What do you think would be the cheapest and best option?

Thanks,
Creighton