Good Morning!
I am new to this forum and plasma cutting in general.
I have a few questions regarding the plasma cutting table.
Thanks,
Good Morning and Welcome to the Forum.
Use a plasma water table additive like sterling cool
There are several different brands out there.
Really depends on your volume and type of material being cut also some people want to see clean fluid every time. so the range is daily to quarterly depending how you operate. I am closer to the later.
The Langmuir instructions say .75-1" from the metal being cut but I can not that reference right now.
keep your water level lower. move you torch over some metal at the end of the cut so the post air flow is not blow straight into the water.
I also have some strips of metal I use as a slash guard I manual place when cutting close to the edge of the table.
I move my electronic box from the factory location and mount to the wall near the table so I have nothing around water and hurt.
Welcome to the forum.
Tin gave you a great run down for all of your questions.
Here is a good comparison of products available including a brief description of just plain ole Borax.
The recipe most often quoted uses sodium nitrite but that product has been hard to come by due to its use in a number of suicides.
Homemade product:
1/4 pound of sodium nitrite powder ($15/pound) “anti-rust additive” NOTE: nitrite NOT nitrate!
1 teaspoon of Physan 20 ($8/8oz bottle) “antibacterial/antifungal additive”
1 oz Ultramarine blue food-grade dye ($5/oz.) “color added so folks won’t drink out of it!”
Mix well, treats 75 gallons of water.
I am new to the CNC Plasma world so I am sure someone will correct me, but I read adding a couple of cups of Borax to the water table helps. I have been using Borax in mine since day one and don’t notice any rust or any other grossness. Mine is due for a good cleaning though… I think I only have 2 hrs and 44min of torch time on mine (according to FireControl)
That’ll work just fine @not_neil_armstrong. We don’t have an official recommendation or affiliated brand we can refer you to, but I’m sure the guys on here will give you plenty of helpful opinions.
I just use the Borax that is on the shelves at Walmart:
But if you want to spend more money, you can but the 2 pack and have it mailed to you:
I guess if one doesn’t have a store nearby, the shipped one may be your best option. 
As long as you are happy with the control of rust, no worries. I actually rinse mine out each day I use it. There has been times that it was as long as 2 months between uses. When it dries out, it is easy do do a quick cleaning of the debris before filling again.
Many people use a cheap shop vac to suck out a bunch of the debris. I bought one of these but have yet to use it due to my revised method. If you table is stationary, this would probably assist in your efforts:
