Sealed it should be fine. Open to the atmosphere, the formation of carbonic acid may have an effect on the kh. As said above its cheap but also its just one of your tools to monitor CO2 levels so do not stress
They do look normal but i tend to steer clear on postal orders as iv been disappointed in the past, i know its not realistic for some. I am lucky enough to live near the shop and the stock is amazing, always satisfied
If you make a DIY spray bar. Ensure the area of the holes you drill are equal to or greater than the area on the original filter pipe. If you do not it will restrict your flow.
I did a custom bar. Its works a treat, get CO2 bubbles everywhere.
The custom spray bar won't reduce flow providing the area of the outlet holes you drill are equal to or greater than the area of the filter piping.
I make a custom one last week. Works an absolute treat. Very effective distribution
It does look like sodium thiosulfate will remove chloramine but will produce Ammonia and HCl as a product. The more i read the more i want a RO unit :P
I wonder if the retail product have anything else in them.
Inspired me too. I struggled to get anything but white pvc. So I bought 1m of 16mm eheim ridigd tubing from the net. So I will get the set up sorted on the horrible white tube before I drill the proper stuff!