plant problem. nutrient deficiency??

[aqua]

hi
my tank spec:
size 4 by 2 by 2
light 6 X 36W 10 hours daily
temp 27-28 cool witH ac fan
kh3 ph 6.4-6.5 pressurized CO2 injection
plants lots of nana, java fern, crypts
water change twice weekly 40% each
dosage after each wc: 15 ppm KNO3, 1.5 ppm KH2PO4, 15ppm K2SO4, profito easylife 25ml

problem:
some java fern has blackened holes and dying off, some with whole leaves turning brown and melting off
some nana leaves have yellow spots and holes

so did i miss something in the fertilization regime??

thanks

[|squee|]

You missed out on trace elements.

Also, there's no need to add K2SO4. The potassium is already provided for by KNO3 and KH2PO4. Profitio Easylife should take care of any remaining potassium needed.

[aqua]

hi

i am clueless about trace elements. can advise me on that??

i thought profito already provides those trace elements? how about seachem flourish?

thanks

[|squee|]

Hmm.. ok I checked their website and they do have trace elements. So either it's not enough in amount, or you're doing water changes too frequently ( keeping nutrients to a low level ). Try changing water only once per week, and divide your dosage into more frequent intervals each week.

How are you dissolving your C02?

[PeterGwee]

What kind of substrate are you using? Nutrients side seems good enough except for maybe GH (Ca/Mg) and CO2 (there is some play in it through the day and measurement errors to be accounted for.)

Regards
Peter Gwee

[aqua]

hi

do i need to add magensium sulphate? co2 wise i am using external reactor run by an external filter, so far ph measurement quite consistent thru the day. thinking of changing to a power head instead, can advise on what type and where to get to run for the 4 feet tank?

as for the base fert i got from na the serra brand (two cans).

thanks

[Sleepy_lancs]

Nope. If you have enough GH, you do not require to add additional MgSO4.