Preventing scale in toilet pipes - chemist please?

[Dellquay13]

To a point as the sea water between sea water level and the outlet needs to have the urine flushed out otherwise the calcium will build up there. and from the head to the water level in the pipe inside the boat up to the water line will also have sea water in the pipe and unless fully flushed would also have aa build up of calcium in that pipe

I have in the past had to remove the whole length of outlet pipe and bash on walk-on to remove calcium.

Ok, luckily I’ve always been zealous about pumping, and then a few more for luck…

 

[oldmanofthehills]

Be careful using hydrochloric acid as I used it in my Lavac and it did remove the calcium which broke off and blocked the outlet which allowed pressure to build up that exploded the pump body.

I fitted an electric pump with a time switch that would allow the flush to be extensive so flush all the urine away reducing the calcium build up

Number of pumps depend on length of pipe between pump and outlet to sea.

As I said it is reccomended to treat the bowl and pipes with hydrochloric as regular preventative maintenance - like many of us you got mishap by delaying maintenance . The going rate is about £4 a bottle and needed at home in Bristol with its calciferous water. I doubt your electric pump and switch was as cheap.

 

[rogerthebodger]

As I said it is reccomended to treat the bowl and pipes with hydrochloric as regular preventative maintenance - like many of us you got mishap by delaying maintenance . The going rate is about £4 a bottle and needed at home in Bristol with its calciferous water. I doubt your electric pump and switch was as cheap.

Point taken.

We use Hydrochloric acid to adjust the PH of our swimming pool so its aways at hand.

We can buy 5 liters of 30% concentrate for less than 6 GBP.

 

[goeasy123]

You need hydrochloric acid/muratic acid on the continent/ brick cleaner cantyaining hydrochloric acid. It wont hurt the loo but flush through thoroughly after application.

The amonia in urine (which is alkali) causes calcium carbonate to precipitate out of the seawater. And the scale then stains. The scale will block your pipes also. Reccomended to treat the system every few years or so.

If you flush through very thoroughly after peeing, the problem is less - 10 pumps not our usual desolatotory 3 to 5

We found citric acid to be much more effective that HCL. To plagiarise my chemist friend…

‘… use citric acid, a coffee measure cup every two days or so flushed down the head. It is a powder solid. It is odor free. It not only decomposes carbonate salts, but also as a chelating agent, it also increases the water solubility of calcium and magnesium salts. While a weak acid, it is trivalent with three acid groups per molecule making a nice buffered acid solution between pH 2 and maybe 8. It's available on Amazon and easily stored in used PET peanut butter or mayonnaise jars.

As an acid it will convert the insoluble calcium carbonate to the soluble calcium citrate and carbon dioxide. You will see the bubbles. As a chelation agent it will increase the solubility of calcium attacking both struvite (calcium ammonium phosphate and/or magnesium ammonium phosphate) and calcium urate.

Citric acid is relatively cheap and not too hazardous. Think lemon juice. Check Amazon.’

 

[srm]

Scale, what scale?
No need for a chemist. It's really very simple.
All that is needed is the minimal effort it takes to flush all waste matter into the sea after each and every use. Never had any scale problems with toilet hoses in almost fifty years of continuous yacht ownership including time spent living onboard.