Dave Gower wrote:

.... Since it is semi-transparent, algae
grows on the inside and constantly gives me plugging problems.

I guess the answer is periodic flushing with an algaecide, so my question,
what can I use that will not be toxic to the soil (I am on septic, not city
sewer). I've never had a swimming pool, so how about the pool algae killers?
Any home remedies?


Anything that kills a naturally occuring plant or animal is not really
earth-friendly. I assume that you really mean "non-injurious to your
chosen plants".

Pool algae killers are basically bleach. A light application of bleach
occasionally will kill the algae. Another possibility is hydrogen
peroxide. The peroxide is probably safer for the other plants. If you
pour a pint into the tubing, then turn the water on, it will be diluted
by the time it gets to the other end.

Other possibilities include getting opaque tubing (black tubing will
absorb heat better in addition to not giving the algae light to grow
on), or burying the tubing. Burying the tubing has the advantage that
you can run it through your lawn without worrying about the mower.
Polyethylene tubing is fairly tough stuff, and will take a freeze with
water in it without breaking, so you only have to bury it a couple of
inches (and you don't have to take it up and store it). However, buried
tubing will not warm the water significantly except in really hot
weather.

I don't think that warming the water is really essential for your
plants. If you are putting the water on the ground around the plants,
the temperature of the soil in the root zone will probably not change by
more than a couple of degrees even if the water is really cold. This is
because there's a lot of soil which can transfer heat to the water while
it's soaking in. Warming water might be important when you're starting
plants in small cells, but not outside.