Caustic Soda and seawater - problems?

[chasroberts]

To try and keep the holding tank a little freer of solids I am considering adding caustic soda via the toilet flush. Is this stupid? I'm not talking huge amounts; just a little, regularly. Any thoughts or comments would be appreciated.

Regards

Chas

 

[VicS]

To try and keep the holding tank a little freer of solids I am considering adding caustic soda via the toilet flush. Is this stupid? I'm not talking huge amounts; just a little, regularly. Any thoughts or comments would be appreciated.

Regards

Chas

raising the pH will tend to precipitate the calcium bicarbonate as calcium carbonate. If you are lucky as a sludge but it may deposit itself on the tank walls and in the pipework as hard scale.

What's the reasoning behind the idea that it will reduce the solids?

 

[chasroberts]

Well it sure rips the **** out of most organic stuff doesn't it. Just trying to avoid occasional block ups (or as I said in the OP; am i just being stupid?) Go on. You can say it if you think it. I won't get offended....

Chas

 

[Bobobolinsky]

A bit of biological detergent now and again, with nice perfume. Note that caustic soda sat in a stainless tank, is not a good idea

 

[charles_reed]

Probably the quickest way to ensure your toilet-pipeworks become immovably silted up, as already outlined by VicS.

 

[chasroberts]

Thanks to all for your input. Plan B then.....

Chas

 

[ccscott49]

Hydrocholric acid, shifts all the scale and anything else! Safe for your seals etc. I treat my heads every month on a liveabpoard boat. Always have for 20 years, no problems, never had blocked pipework.

 

[chasroberts]

Hydrocholric acid, shifts all the scale and anything else! Safe for your seals etc. I treat my heads every month on a liveabpoard boat. Always have for 20 years, no problems, never had blocked pipework.

No problem getting hold of HCl here. What strength would you recommend. Tank is plastic btw not s/s.

Thanks in advance.

Chas

 

[vyv_cox]

I use the 500 ml red bottles widely available in supermarkets. Some are marked up as 20%, others no indication. I use them as they come, flush through a third of the bottle at a time, wait until the bubbling stops, then add the next. For the tank only flush the whole bottle through with the outlet closed, then go sailing.