Surface Film, Copper and DIY heating cables

Subject: Surface film

> Bob_Hoesch at fws_gov wrote:
> >     My (densely planted) tank 
> >     throws out enormous amounts of floating film and scum, and
> >     extractor keeps the surface completely clear.  It's a bit 
> >     to maintain, as it is very sensitive to water level and it
> >     get clogged with bits of debris. Also it's not as inconspi
> >     like.  But it does an essential job.  I don't know of bett
> >     except a built in spill-over.


> I did not know that plants produce floating film and scum. Can a
> explain in simple terms how that happens? I have mixed floating 
> (duckweed, frogbite and Pistia: did I spell them right?)in my 18
> in addition to a good number of submersed plants (mostly swords,
> Crinum). I normally have little or no floating film despite a me
> load (no surface extractor) and I thought that the root system o
> floating plants absorbed it in some way. Does this make sense?

I have a number of tanks, some with floating plants, others 
without.  None of them have surface extractors and none have much 
of any surface agitation.  I don't have surface scum in any of 
them.  I've once or twice seen it in non-planted breeder set-ups, 
but never in one of my planted tanks.

Subject: copper in the water

> Karen Randall wrote about not being able to grow Valisneria beca
> sensitivity to copper.
> Karen, I used to be in Boston, and the water there had 5 mg per 
> copper.  After standing in a tank for a month, that water would 
> snail in 30 minutes and a fish in four days.  I figured that oth
> kept their fish alive only because they used activated charcoal 
> filters that captured the copper.  I didn't want to do that, so 
> the problem by borrowing some 5 gallon plastic containers from a
> and going to the outflow from one of the local reservoirs and co
> water there.  I filtered the water through sand to catch any hai
> that might have been picked up and kept it in a covered aquarium
> excellent water and I never had any problems with it.  In fact, 
> wondering if all that copper was OK to drink, and I began drinki
> water I had collected.  No problems, and I am still here to tell

Gee, I'm glad that there's someone else who's actually experienced 
this problem!<g>  I was worried enough about the copper levels 
that I did check with the pediatrician about it, but he said it 
was within acceptable limits.  

If I had less tanks, kids and horses, I might be tempted to 
collect water somewhere or get an RO or DI unit.  As it is, at 
least for now, I just work around it.

It is a royal pain in the, uh, neck, though!<g>


Subject: DIY substrate heating

> Hi Karen,
>   I'm sorry to hear that your foray into substrate heating 
> didn't work out.  From your description I would guess that
> the problem wasn't caused by a fragile (broken) wire,  but
> by a failure of the insulation at some point. Probably one
> of the connections was not properly sealed, and some current
> started flowing to ground through the water. I don't remember
> what method your friend used to seal his connections; I used 
> several layers of heatshrink tubing on my setup, and it has 
> worked very well.

I really don't know where the failure occurred. I didn't mean that 
the wire actually broke, I meant that the insulation had been 
compromised.  But, you are right, it could have been anywhere.

> By the way, that Bolbitis you gave me is growing like crazy!

Great!  It's a pretty plant.  Unfortunately, mine is again growing 
like crazy too!<VBG>  

(For those of you who couldn't attend this little AGA/APD/BAS 
"happening", I removed about 60% of the plant mass from this tank, 
and it still looked fully planted when we got done... I think some 
rearranging was definitely in order whether substrate heating got 
installed or not!<g>)


Karen Randall
Aquatic Gardeners Assoc.
Boston, MA