Problems with holes on leaves

Hi all the net people,

Into my 50g tank I have these types of plants: 15 Hygrophila Polysperma,
4 Nomaphila Stricta, 10 Elodea Nuttalii, 2 Anubia Nana and some Echinodorus.

Fishes are : 9 Neon tetra, 6 SAE (perhaps false), 5 Chorydoras.

The tank has built into a biological filter of 10g and I use 20 cc/daily
of PMDD (as formula in previous mails of net), with DIY yeast CO2 direct into
power-head impeller.
No snails at all (I checked during night and I am sure)

Water values are: GH = 13   PH = 6.5  temperature = 28 centigrades  FE = ~ .1
The actual lights are 2 x 30 watts lamps x 12 hours. 1 is Triton other is Growlux.
This last old and exausted.
End of current month will change with 4 x 18 watts... Biolux pentafosphor.
Will new lamps be ok? Someone has experience with them?

My problem: because stem plants grows quikly, every 2-3 weeks the leaves come
emersed from water. This isn't good because firstly the tank has
only 1 inch of gap between water and covering glasses and secondly
makes too much dark on bottom.
The matter is that every 15 days I am obliged to take stem plants out of
water, cut 10 inches about on bottom (pratically 90% of roots)
than replant it in gravel. This makes the Nomaphila not happy at all... and
the leaves start making holes in middle and becomes transparent.

I think that this type of plant keeps nutrients from roots, thus cutting
them is a shock for the plant. Am I correct? Is there some one helping me
to solve matter?.
If I don't cut the plants they come emersed and leaves
near light are full of green algae.
My 5 SAE (hope will be true Sae and not false) continously eat the green 
on leaves but is not sufficient and this green is ugly to see :-(

Am I working correctly with these plants? I don't think that holes
and transparency are normal.
The other plants are quite good. On past I had transparent leaves
on Hygrofila Polisperma, but encreasing PMDD now are ok.

Same transparency of leaves I am also having on Echinodorus
expecially those on direct light, but one with less light is ok.

If someone could help me TIA.

Ciao  Ezio                     _ _
___________________________,,,_o o_,,,________________________
       FERRO Ezio               -        Torino - Italia  
Quando il gioco si fa' duro,        When the going gets tough,
e' il duro che inizia a giocare.    the tough get going.