DI & TWP Recharge Kit Formula
The following document provides the necessary information to purchase and formulate your own consumer grade replacement chemicals similar to those found in the DI & TWP Recharge Kit.
Here are the mixing directions for the chemicals, plus off the shelf products to purchase so you can mix in small quantities.
The two chemicals should be obtainable locally in small quantities for a low price.
The ACID component consists of (diluted) hydrochloric acid 31 degree baume, you can usually purchase it by the gallon from any hardware store under the name "Muriatic Acid", it's used for cleaning mortar from bricks and etching concrete. You can also get the same thing from a swimming pool store used to adjust swimming pool pH.
The ACID FORMULA used in recharging is 14 degree baume. Basically it's a 50/50 mix of water and acid. If you use a 12 ounce plastic bottle, add 6 ounces of the acid FIRST and then add 6 ounces of water. DO NOT ADD THE WATER FIRST.....
DO NOT BREATH THE SMOKE THAT COMES FROM THE BOTTLES WHEN MIXING. The acid is a very strong concentrate. It is a little safer once diluted to recharge ratios.
The BASE component may be a little harder to find, I know I have told a couple of other fellow's how to mix it and they found different brand names, in their respective countries, as well as the brands we have here.
Before I go on, I want you to be very very careful when you mix the BASE component chemical with water, very high heat is produced as the reaction of mixing with water and you must be prepared to cool the capped bottles down before the heat burns your hands.
The BASE component can be purchased at many groceries stores, most hardware stores and almost all plumbing companies. It is "Lewis Red Devil Lye" or any other brand of LYE that is PURE LYE, not Draino or drain cleaning mixed up formulas, it must be 100% pure lye.
The FORMULA is a little wierd in the way you measure it. This is a granulated solid crystal and is sold by weight, usually in 12 ounce cans.
We use 3 ounces by liquid measure to get the right specific gravity to allow separation of the resins. Thus you only get about three 12 ounce bottles of the recharge fluid out of a can, even though the can is 12 ounces by weight.
Editors Note: A more convenient way to mix the Cationic Recharge Fluid formula is to use a larger glass container, such as a glass coffee pot. Place the entire 12 oz can of Lye into the container and then add RO or DI water to bring the level up to the 36 ounce mark on the container.
WARNING: High heat is produced. Do not package until mixture has cooled.
Keep away from children.
Continuing with our instructions from before the insert.
AGAIN, the bottles must be DRY. Have the cap for the bottle at hand.
Fill a sink or bucket with enough cold water to cover the bottle.
Measure, using the liquid measure scale on your measuring cup, 3 ounces by liquid measure of the Lye Crystals and place this in your bottle. The bottles should be 12 ounce plastic bottles, by plastic I mean the kind that looks like plastic milk jugs. Sorta frosty looking, not clear, or white bottles, HDPE type.
After you have the 3 ounces of LYE in the bottle, place the lid to the bottle in one hand and hold the bottle near the top in your other hand.
Fill the bottle close to full, quickly screw on the cap, and drop it into the cold water bucket. Allow to cool for at least 15 minutes.
You can reach into the bucket and squeeze the side of the bottle to break the crystals that will form a solid, but they will dissolve without you doing that, only slower. To speed up the process, I shake the bottles occasionally during the 15 minutes and place them back into the water.
You will notice that the bottle gets a vacuum in it, no it doesn't swell up like you would think, reverse psychology of science I guess. Well anyhow, after the bottle feels cool enough to hold, loosen the cap and let some air in, if it doesn't get too hot, you can go ahead and fill it the rest of the way with water or to the 12 ounce mark if you are using a larger size bottle.
Always allow the BASE chemical mixture to sit at least 24 hours before using it to recharge a DI column or you may get heating of the DI resin.
Here's a little money saving tip!
If you have built a separated bed DI system, you can dilute the BASE mixture up to 25% and save some dough. But if you are working with mixed bed cylinders it must be 3 ounces Lye by liquid measure to 9 ounces of water or you will not get the resins to separate. Too much Lye and the blue resin will float also. It's the Specific Gravity of this Formula that allows it to separate the resins properly!
The ACID comes in gallons for about (at the time of this publication) 3 bucks a gallon here and the BASE crystals come in 12 ounce plasti-cans for a little over 2 bucks, some stores here charge 3 bucks but those are far and few between.
Don't forget to change your carbon about every 5th recharge to keep chlorine from passing through into the resins and bleaching out the color indicator of the cationic resin.
Again, be very carefull.
Oh, I might warn you about a unique weather phenominon that can and probably will occur in your home at some point. As you pour the acid and or add water to the bottle, you may notice that the air in your home becomes a faint white cloud. Even in the most remote parts of the house. I was told by the manufacturer that this air is not harmful, but it's just one of those things that happen. I turn on the exhaust vent on the stove and it still happens from time to time, depending on the temperature of your home, usually between 68 and 74 and a humidity of 45 to 60, which is the ideal temperature and humidity to create the faint white cloud as the ACID sucks ions out of the air. That's what I wanted to say, it takes from rather than puts into the air and causes the ion imbalance and the clouding.
What's really wierd is that you will not usually see the cloud in the room you are in, but rather in remote parts of the house as the ions are sucked out to the next room in the chain toward where you are.
I think that about covers the only scare you might get from mixing your own chemicals at home.
If you would like to do recharging for your local pet shops or your friends, that's perfectly OK with me. We usually charge the pet shops 5 bucks and they in turn charge the customer 7.50, but that's here, you might charge 7.50 and let them charge 10 bucks.
Last but not least:
After numerous recharges, you may find that the color indicating dye on some brands of resins begin to show the unit is rapidly exhausted, when in fact there are many more gallons of purified water available. To alleviate this, set aside a few ounces of the color change resin to place in the top of your cylinder at a later date, if this becomes apparent.
You can also take a clear medicine bottle with twist on type cap and make this into a reactor that holds the cationic or color change resin, and place it as the last cylinder in-line before your water container.
When it changes color, it's time to recharge. Save this resin to make another cationic cylinder down the road and refill the medicine bottle at each recharge.
To make the indicator bottle, drill a hole in the cap and in the bottom of the medicine bottle, the size of the hoses on your DI unit. Push the hose inside of the bottle and install a short 1/4 inch long piece of rigid tubing that fits snug inside the hose. Then pull the hose back through the hole so that only 1/8 inch remains inside the bottle. Under normal circumstances this HomeBrew fittingless connection should never leak. Repeat the same proceedure for the hole in the cap. Use a filter sponge in the top and bottom to sandwich the resin so it doesn't leak out of the hoses.
These tricks and many others, can be found in the book "Simplified Reef Keeping" by Robert Metelsky!
Please do be careful when handling chemicals of any type or strength, and keep them out of the reach of children. Never leave an open or unmarked bottle where anyone can be injured by it.
After you have done this a couple of times, and have gone through the Recharge Process, it's a whole lot easier than the lengthy directions are to read.