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April 2000 Selected Articles |
Hi Koi Lovers - President |
Office of Sec. - Anne |
Electrical Safety /GFIC by Dr Johnson |
Well, April is here and that means it’s time for our small fish show. This year it will be held on Saturday, April 8, from 9-4 at Hagan Ace Hardware - 12548 San Jose Blvd. In Mandarin. Twelve members will be showing their small fish, 10" and under from tip of nose to tip of tail. Set up for the show is on Friday, April 7, starting at 4 PM. Volunteers are needed to help with the set up on Friday or with the clean up on Saturday at 6 PM.
The All Florida Show at Splendid China had a very good turnout, including quite a few members of NFKC. Many of our members went down early to help with set up, security and other various jobs. Volunteers from NFKC included Rod & Bonnie Lawton, Todo & Sandee Todorsky, Jon Lockerman, Linda O’Steen, Ann Miller and Terry Carter. Charles Gardner made a beautiful Friendship award that was presented at the award ceremony. Thank you to all of you for giving up your own time for this event. I hope I have not left anyone out.
Hopefully, those who attended were able to purchase some nice fish or supplies. I know I purchased more fish than I had intended!
Thank you to Bob & Peggy Morris for hosting the March meeting in their beautiful home. They have such nice property and their pond blends in so naturally with the landscaping. We raffled off a lot of small fish that were donated to our club by the Caler’s, and a larger koi donated by the Todorsky’s, as well as a filter from Charles Gardner and food & pond chemicals from Rod Lawton. Thanks to all of you for your donations!!
Please try to attend the small fish show on Saturday. This is a brand new Ace Hardware with a very large garden area, so we expect a lot of interest in our fish. The show will also serve as our regular April meeting, so come and enjoy, and good luck to those showing fish. See you there!
Jim Roberts
Office of the Secretary by: Anne
Another beautiful day for March’s meeting. Bob and Peggy showed us a warm welcome, a beautiful yard, pond and home. Peggy and Bob have a delightful English garden surrounding their home and pond. It was very interesting to see how they have dealt with water run-off from their yard towards the pond. It was educational to see their filter and pump set-ups. Some very artistic and clever work has gone into their pond and it’s surroundings.
Jim explained that there is a problem with the new Ace Hardware in Mandarin as the site of the Young Fish Show, hope that information about the new location will be contained in this newsletter.
The meeting was then turned over to Rod Lawton who had information about the new Aeromonas/Pseudomonas treatment "Lymnozyme". This is a great boost to our hobby and fish. The product hadn’t been shipped yet but should be available at the April Young Fish Show/ meeting or soon afterwards.
AFKAPS started Friday the 17th and ran through Sunday the 19th, Our club was well represented. Many of our members could be seen buying plants and fish, I am sure they had as great a time there as I did. There were many vendors with new and very interesting merchandise, displays, and beautiful fish for sale. If you wanted something new for your pond or pond landscape it would have been difficult to leave empty handed. Fish dealers from California, Pennsylvania and other states had booths and tanks there, as well as from our own state. The seminars were very informative, with Doc Johnson from Atlanta giving two different talks on fish health and disease. Other seminars were on UV’s, filter construction, etc. If you haven’t gone to one of these shows, it is well worth planning on attending the next one.
Sherri Brown is our new Librarian, if you need to return or check out any material see her at the meeting.
Meeting attendance: 39 plus guests
Koi Chat with Sandee
Tracy & Geneva Jackson are among the oldest members in good standing of the NFKC. Tracy joined in 1985 about the time of the Fall Show (which used to be held over two days in the old Roosevelt Mall). It was at the show that he obtained his first Koi, a 14" Sanke that he got at auction for $35. The Sanke went to the pond that Geneva had her sons build so she could keep goldfish. But 6 months after Tracy joined NFKC, Geneva became a member. And soon the goldfish pond became a Koi pond.
The pond itself is 19-1/2 feet long and 9-1/2 feet wide. Tracy says that the pond itself holds between 1500 & 1600 gallons with an additional 200-300 gallons in the filter system for a total of approximately 1800 gallons total.
Over the years the Jacksons have lost track of the number of awards their fish have won. But there are a few that are quite memorable. At the first Fall Show after becoming a member, Tracy did not show fish but did stand guard over the fish until the mall closed. For his efforts Tracy received a Koi made of crushed coral from Hawaii and was included in the article in KOI USA about the show. Another year produced a Rice Bowl as award for his efforts. In 1994 Tracy won the AKCA Award for his Black Crow. And in 1999 he won the Friendship Award from Orange County for his Showa.
When asked about an interesting, funny or terrifying story about the pond or the fish, Geneva recalled coming home from a birthday party and finding that the cricket cage that had been placed over the intake and held in place with a rock, had been knocked over by the fish. She got down in the pond and pulled the Black Crow out of the intake. She says she walked that fish back and forth in the water for over an hour trying to save it but in the end her efforts failed. Another time they were visited by a raccoon that nearly emptied the pond of show fish in a week's time. And one of the most heartbreaking stories was when they were battling an aeromonous outbreak. They were told to put salt in the pond but were not given instructions on dividing the dose over 3 days. They lost all but 6 fish in that ordeal.
As for advice they would give to new Koi Keepers: ask lots of questions, and get help from someone who knows about something new you want to try, and take advantage of the resources within the club including the library.
Electrical Safety: This article by Dr. Johnson may be a little technical for some members, but your safety and that of you koi may be at stake.
GFCI - the inside scoop from an Engineer -
Knowledge is power, so here's the inside scoop on GFCI's:
The current generation of garden-variety GFCI's do not have anything to do with the ground wire. No kidding. The ground goes into the unit, serves as a zero-potential reference to the internal monitoring circuitry, and then passes right through it *without* being monitored. (Exception: Medical grade units...explained later)
Current-generation GFCI's employ two very sensitive bridge amplifiers. These amps each monitor a leg of the AC circuit. Amp #1 monitors the "hot" wire, and amp #2 monitors the neutral. The ground wire goes straight-through the unit 99% of the time (see below for exceptions on "medical" grade units). The outputs of amp 1 and amp 2 are directly proportional to the current flowing through each of these legs. Their outputs are routed to an analog comparator. As long as both amps show the same output level, the comparator's output is off. The comparator is connected to either an output driver stage (which is either a disconnect relay or a slow semiconductor like a triac).
To trip the GFCI, all that is required is a very slight current imbalance between the hot and neutral wires. This difference gets amplified and the difference causes the comparator to saturate... which "trips" the output stage thereby disconnecting the power. This all happens in just a couple of milliseconds. Enough to zorch a fish in close proximity, but not enough to kill a healthy human.
Depending on the intended use of the GFCI, some employ some smarts to prevent false tripping. Some equipment has internal circuitry (ie capacitors in the power supply) which will shunt a small amount of current from hot to ground when it is initially powered-up. This will cause a "trip" on some units unless the unit is smart enough to "cycle count" (ie, look for the trip condition on two successive cycles of the AC line. This trades raw response time for convenience).
Now, for a variation on this basic GFCI theme we have the ultra-high-end medical grade" units. These employ a very high gain amp (to the tune of over a million to one) which monitors current on the ground lead. (The other 2 amps remain exactly as described) If *any* current whatever is flowing in the round lead, it trips the unit. (This type of unit is generally configurable as to its behaviour. There are times such as when a cautery is in use, where there will simply *be* a current flowing in the ground pin even though there is no actual "imbalance". This type of leakage causes false trips, and the last thing you want if you're a surgeon is to hit the juice when you've got a field full of bleeders... and the entire OR goes dark!).
Medical units also have what is called an "output crowbar". This is a
nice, hefty and very fast semiconductor clamped directly across the hot and neutral leads.
When an imbalance occurs, this semiconductor saturates and provides a
direct *short* across the unit. The usual output stage disconnect stage is also given a
command to "unlatch" at the same time. Its a double-whammy.
So why the crowbar? Sheer response time as well as a certain degree of redundancy. When the output is crowbarred" (the name came from some wag who equated this action to dropping a metal crowbar across the output leads) no current can pass *out* of the GFCI.... although quite a lot is flowing *inside* it. Electricity takes the shortest path to ground... and the crowbar definitely provides this path in spades. This direct short is present for several milliseconds... until the output stage (which is much slower than that last semiconductor) can disconnect itself. This buys you time. The human body can take an utterly unbelieveable amount of both voltage and current for a few microseconds. (Basically, electrocution affects the muscles first. Muscles just can't physically get pissed-off in such a short time. Yeah... you'll be spastic in the morning, but 50,000 volts for a couple of microseconds will *not* kill you. Not enough time. Admittedly, neuro effects are another matter... You're alive, you're breathing fine, but you can't move your legs for a few weeks... hehehe)
A Related Roark Tip: This brings-up another point which I'm about to go harp-on
for my web page. Folks with submersible pumps can dramatically reduce the possibility of
shocking fish in the event of a pump electrical failure by placing their pump within a
basket of aluminum window screen. I use nylon wire ties to secure the screen into a
"baggie which fits very loosely around the pump. This
conductive wrapper gets grounded via a separate copper wire to the electrical mains
ground. If the pump goes kablooey, the screen forms an electrical shield around the
"hot" pump.... and protects the fish. This dramatically reduces stray currents.
It also encourages the GFCI to trip under very low levels of leakage (the juice doesn't
have to go very far to find a ground... and in water, every inch of distance is
resistance... and current is a product of voltage and resistance, so, by decreasing the
distance to a good ground you've increased the current flow, which will cause the GFCI to
trip for even minor leaks). This basket also works as a utilitarian prefilter of sorts.
The down side to this is the aluminum decays in about a year and must be replaced. The
*upside* to this is the pump is protected by this sacrificial anode action. The koi don't
seem to be aluminum-sensitive. Nothing I've ever read includes aluminum oxide on the
"koi kill" list. Technically, it isn't a heavy metal and has no known
side-effects (except in us "higher" mammals where it has been linked to
Altzheimers disease and neurologic disorders).
www.koivet.com Dr Johnson
Hi Koi Lovers - President |
Office of Sec. - Anne |
Electrical Safety /GFIC by Dr Johnson |