When we lived aboard, we didn't think much about the water tanks. Correction. We thought about how full they were, but that was the limit. In the Bahamas we got water periodically in two 5-gallon jerry jugs. This kept the tank levels steady. In the US, we had a 30 gallon bladder we used. Fill it up at a dock. Pump it into the tanks. Worked out really well.
We churned through a lot of water. Something like 10 gallons per day.
We went back to shore life and water sat in the tanks.
CA has been trying to find a way to clean them. They don't leak. The paint is reasonably intact (a rarity in boats this old.)
We'd like to replace the two big tanks with four 35-gallon Polyethylene tanks. We give up about 20 gallons of volume by doing that. But the installation seems to be simple.
(Tank Mart seems to have a tank that's 33″×28″×9″. We think that can be fit through the openings.)
What we did was this.
Drain them. The sink pumps work to a point. Then the water's too low for the pickup tube. The pump we use to transfer fresh water from the bladder to the tanks works well to pump water out. It's a lot of water. Patience helps.
The last few inches have to be pumped out with the shop-vac. This works out well because it gets the sand, grit, and general yuck out of the tank.
Scrub the parts the can be reached. A long-handled scrub brush and yoga help.
Rinse with the high-powered dock hose. Vacuum out the grit.
Rinse with the high-powered dock hose. Vacuum out what remains. This water tends to be pretty clean, actually.
This year, we're also going to "shock" the tanks. Clorox at a concentration of ½ oz per gallon (a quart per tank, more-or-less.) Run that through everything for a while, pump it out, and replace it with ordinary dock water.
The rinse with the deck hose and pump with the shop-vac seems to be a very workable way to clean the tanks. When we haul out in the fall, we intend to try that again.
Next up? More cleaning.
And the deep bilge pickup hose seems to be clogged. I replaced the float switch. Tested it. And it didn't suck. The upper-end pump works. The lower end is decidedly not working.
We do need to get out of the slip. Maybe Tuesday, 4th of July? Depends on how complex the pump issue is.