water tank

Is the plastic taste coming from the hose you are using to fill it?

As above, don't use an ordinary garden hose to fill the tank. Only use food grade hose.

Are the hoses from the tank opaque plastic or clear. If they are clear then Algae can grow in the pipes and you'll get a bad taste.

You can get rid of minor smells by dissolving around 500 grams Bicarb Soda in water and pouring it into the tank. Then fill the tank and let it stand for a day. Drain and flush.

More drastic action is about 2 cups of White King, Chlorine Bleach, added to the tank then fill it and leave stand for about 2 hours or so. Drain and flush well by filling it a couple of times then drain.

Milton works well, give that a try?

You could also use a B.E.S.T filter on the end of your hose when filling up if you don't already use one. There good for 5000L and no need to change filter papers, just back flush.

I've found that white vinegar does the trick

Whitworths Boat Chandlers sell a product called Starbrite tank water conditioner. I've used it for years to keep the water sweet for months on end, never have taste issues.
Once a year I empty the stainless steel tank then dissolve 2 -3 cups of 'Nappysan" (its a type of salts) into the tank then fill up the tank run the solution thru the lines so that it is completely thru the system then leave it overnight.I then flush it thru a few time then refill the tank as normal and all good for another year This removes any growth in the tank and lines. Since starting this regime I have rarely seen algae or noted any bad taste.

Cheer ....Jeff

Whitworths, being ship's chandlers, sell a number of tank cleaning products.

Worth a look at their website.

Got lots of other good gear too!

Bob

I have read somewhere (can't remember where, I think on a water treatment site), that to remove the bad taste from plastic water tanks, add 2 litres of neat red cordial to the tank, fill tank with water, and let stand overnight. Next day drain & flush tank, using water grade plastic hose to fill. Try "googling" the subject and see where that leads.

Macca.