Muriatic Acid. Use Long term

Antoniocastro · Aug 29, 2018

Hi everyone's
I'm planning to use IO sea salt . But I need reduce alk to 9 dkh, I planning to use muriatic acid in the mix for reduce alk.
My Question is :
There is any negative long term effect using muriatic acid for water changes?
Thank you.

chipmunkofdoom2 · Aug 29, 2018

As long as you aerate the water properly, no. Hydrochloric acid is basically just hydrogen ions. After off-gassing the excess CO2 formed, the only result is lower carbonate alkalinity. This assumes you buy a sufficiently pure HCl substance. However, because you're using the acid in such small quantities, it's unlikely (although still possible) that most impurities in the HCl would cause any negative effects on the tank.

You might not need to reduce alkalinity at all though. Instant Ocean usually has alkalinity around 10 dKh. If your goal is to keep your tank at 9 dKh, doing a 25% change with water at 10 dKh will only increase your alkalinity by 0.25 dKh. Even if your tank is 8 dKh, doing a 25% water change will only increase your alkalinity by 0.50 dKh.

madweazl · Aug 29, 2018

It usually mixes up at around 10.7 dKh for me but I do agree that the difference may be negligible depending on the amount changed during the maintenance.

Antoniocastro · Aug 29, 2018

Thank you everyone!
The purpose of my post is cause I want to use this method constantly..
In my last tank used to change 20% weekly.. and in this I want do the same process..

madweazl · Aug 29, 2018

I've been using it for at least a year now (low fume variant) without any issues that I can contribute to the muriatic acid. I generally change 12% weekly but just did a series of three, 25% changes over the past week and a half because I was having issues. I ended up finding a corroding magnet on a float sensor bracket which I believe was the problem but dont know for sure. Things are on the mend now.