String algae issues

Hi group,

I was hoping some of you might be able to suggest some ideas to help
control our string algae problem. Thanks in advance.

Our pond is approaching 1 year old now. We have about 5400 gallons
with a depth to about 45". One large 4' wide waterfall that is fed by
two Savio biofall filters. A powerful external Sequence pump that
pulls thru a Savio skimmer. We do not have a bottom drain. We have
city well water which is hard and higher in PH. Next year I plan on
adding a whole bunch of lilies since I suspect that the sun is my
biggest contributing factor to the algae growth. We have snails and
the the bullfrogs also seem to enjoy the water feature. We have 11
koi which average about 5-11" in size. We also have about a dozen or
so of what we think are schubunkin. A friend has been providing water
plants and obviously eggs attached to them so now we both have baby
schubunkin that are approximately 3-4" in both of our ponds. I was
also wondering if schubunkin will cross breed with koi or goldfish
since he has these three types in his pond. We are mainly in sun in
our chicago burb backyard. I would guess we only have about 20% of
our surface water utilizing plants. Our salt level has been high but
we still have been able to grow lilies, iris, cattail and some
pickerel. Water hyacinth, lettuce and millfoil are growing but are
not very healthy. Our water was tea colored earlier this year but
since then the tea color has disipated and I have gone thru a few
algae blooms. We even had the pea color water about 2 weeks ago but
since I added a UV sterilizer that problem is under control. I have
been activly using Microbe-lift products like spring cleaner earlier
this year, PL and even just started Ensure for better plant growth. I
have been using their liquid barley extract which in my mind is not
controlling the string algae all that great. Our salt level this
whole year has been high and right now is at the .08 mark after we did
a 60% water change last weekend. Our PH has been high all year and in
the middle 8's. Our hardness has been in the high range 250-425. Our
alkalinity has also been in the high range from 240-300. However, our
ammonia and nitrite ranges have always been in the safe zones. I have
tried a product called Baraclear and it works very well although they
tell me that it could not be very safe for the fish if your PH is
always in the high range. Since using an initial dosage of Baraclear
it seems like it controlled the string algae pretty good and I was
thinking of using it like as a monthy treatment. But since Ive heard
that it might not be safe for fish in a high PH environment Im
skeptical about using it regularly.

Should I be that concerned about controlling my PH to an appropriate
evel or should I consider is somewhat normal in my conditions?

Is the PH level a main factor in the string algae problem?

Other ponders in my area even those using lake Michigan water not well
water have reported higher PH levels. I have been told to try some
muriatic acid in very small and slowly disipated amounts to try and
bring my PH down. But by doing this and trying to keep my PH down to
a safer zone will it be a regular maintenance ritual? Acid is not all
that safe so should I just concentrate directly on how to control the
string algae and not so much on my overall PH levels?

Rick