Join Date: Jan 2007
Location: The house is in Kingsport, TN. Boats are on Watauga Lake and in New Bern, NC
Thanked 51 Times in 46 Posts
Rep Power: 11
I have a SCAD single tank monitor on my holding tank with the aluminum tape strips mounted on the outside of the tank wall inside the cabinet door under the vee berth.
The unit is perhaps three years old. When new the high level light never lit (15 min of high level should trip the light to on), and it had to be returned for repair/replacement. I have a clear insert in the 4" Beckson inspection plate in the top of the tank which I clean annually when I scrub the tank out. It allows me to see into the tank. The level that the SCAD unit reports is a bit variable. I would guess it to be +/- 10 to 20%. In addition, the indicated level drifts as the "sandy brown solids" accumulate on the sides of the tank.
I have confirmed the drift by pumping the tank empty then adding seawater to the tank from a 2.5 gal bucket through the pumpout line noting the amount of water added when the display goes from E to 1/4 to 1/2 to 3/4 to F to running out the vent.
I wondered if there was plywood within the tank wall as the SCAD instruction manual warns against using the foil strips if plywood is present. I called PSC this afternoon and asked Thumper. While he could not vouch for a 1988 boat, he did not think the wall would have been reinforced with plywood.
In short I have it, I use it, but if I really want to know how full the tank is, I raise the vee berth cushion and look through the deckplate.
1988 PSC 34
Last edited by wsmurdoch; 12-08-2011 at 07:45 PM.