Been going around in circles the last few days with chemistry and maths! I remembered that my issue with space was the reason I went with ATI in the first place. I currently have 2x2Litre ATI Pro bottles that cover everything. I can squeeze another 2-litre bottle in with a bit of a push so I can move to a DIY ALK+CAL and Tropic Marin Part C method.
I think the limiting factor and managing to squeeze enough into 2 litres to cover my usage while away for 7-10 days was Alk. I need to dose around 1.5-2dkh per day in 1300 litres. I was only looking at Sodium Carbonate and Sodium Bi-Carbonate. Then I found your recipe for using Sodium Hydroxide and believe I could use this and is possibly what ATI use to squeeze in lots of ALK to those 2-litre bottles?
https://apcpure.com/product/sodium-hydroxide-pellets-99-9-acs/
The issue is I can't work out the dosing amounts. I want to base my dosing off the least soluble chemical to get as long as possible between refilling the 2-litre bottles. I'd like to create the solutions with the same strength so I can dose the same amount out of each bottle so adjustment of ALK/everything is easy and without having to re-calculate everything.
Is there any chance you could guide me in the right direction to work this all out? Thanks.