Cleaning the water tanks

[SailRxSin]

RxSin is hull #353, 1982.  We just got her in December and recently inspected the water tanks and they are disgusting.  a significant layer of brown sludge has built up and as everyone here knows, very limited access to the interior of the tanks for cleaning.  I have ran bleach with water through them but this has not helped. 

I wish I could find a small power washer with a flexible shaft to help clean.  Does anyone have any ideas or solutions for me? 

Thanks,
Skipper

[popeye323]

Hi

I recently searched the internet for cleaning water tanks and read that for plastic tanks to use vinegar. I used a half of cup for each tank. I let it sit in there for several days.  It seemed to make a difference in my tanks but they were not as bad as yours sound.

Good Luck

Steve
Total Chaos  # 360

[selene]

In extremis - I remember reading a tip from a lady who title herself 'The Head Mistress', and is an authority on heads.  For really dirty holding tanks, she suggested putting non-foaming detergent into the tank, and then a bag of ice, then go sailing.  The ice bangs around, rather like an internal scrubbing brush, loosening any deposits, with the help of the detergent. And when all is done, the resulting liquid can simply be pumped out. I wonder if that approach would also work for water tanks? There are no baffles...

[SailRxSin]

Thanks to everyone for the suggestions

[sfomarc]

I have a 32 Pearson and took out the starboard tank and power washed the inside.  I am also replacing all the original water lines.

[Last Resort]

I had this funny hose on my boat when I bought it and it took a couple of years to figure out what it was....it's a hose to clean out the holding tank!!!  You attach it too a hose and the end sends out a 360° spray, and quite powerful. So I imagine if it can clean my holding tank, a water tank should be no problem. It's the next best thing to an actual power washer I think

here's mine, but there are different versions to research!

https://www.amazon.com/Valterra-A01-0187VP-Flexible-Tank-Wand/dp/B000BGHYE8/ref=sr_1_11_mod_primary_new?dchild=1&keywords=black+tank+cleaning+wand&qid=1605664789&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=8-11

[#95]

The bow tank on #95 was just nasty as heck, and contemplated different methods to get it CLEAN....removal of tank and steamcleaning, a flexible pressure washing wand, nope. I ended up cutting a square access point to allow me to get my entire arm in there to scrub, disinfect, rinse and rinse some more. I found a good plastic welding tool at HF for 22$. It made quick work of re-sealing the cut area. The entire process took me just over 2 hours while taking my time and doing a full recovery of the tank.             https://www.harborfreight.com/welding/welders/plastic-welders/80-watt-iron-plastic-welding-kit-60662.html