Potassium as a water softener...ok?

[Jeremy Wheaton]

Hi guys, I've finally cycled up my new AP system. I'm on a well out here in Montana, USA and have extremely hard water. We have dogs and houseplants and opted not to use a salt based softener and chose K-LIFE sodium free water softener for our home. Here's what the package says on it as far as what's actually in the softener:

Potassium Chloride    98.9%

Sodium Chloride        .9%

Calcium                    .02%

Magnesium               .01%

Bromide                    .04%

Sulfate                      .04%

Water Insolubles        .01%

Moisture (105 degrees C) .10%

I have a couple questions and an observation with this in mind...

Question 1. Is this something that I will see problems with if I continue to use it as a top off source of water? I add about 10 gallons every 2 days to my 375 gallon setup. This is in the winter with the room at about 68 degrees by way of a small floor heater. The summers get super hot and dry, I will probably add twice that amount every day at that point...

Question 2. Will my PH ever stabilize with this? I currently add about 4TB of PH Down every week or so to keep it at around 6.8-7.0.

Observation: See the pic below for this one. It looks like my hydroton is covered in sugar when they dry out. I've tasted it, it's not salty at all and it easily flakes off. Is this just the mineral deposit from the potassium? Is it something I should be concerned about?

And here are some more pics of my setup since I was taking photos. Please feel free to comment or ask questions on it if you want to. Thanks for your time group!

Seedlings are coming in nicely. I planted these about 3 weeks ago. Mostly lettuce and some culinary herbs.

I built the growbed with my friend in an afternoon (he's a heck of a carpenter). It's 4'x8'x10". The bed fills up in about 30 minutes and drains in about 5 minutes. Are these acceptable times?

My IBC tank holds roughly 275G. The sump tank (below the GB holds 100G). I just added 6 koi to the tank. They are only about 4 inches long right now, but they are eating and come up to say hi whenever I enter the grow room.

[Glenn Davis]

Yes potassium chloride (KCl) is safe to use as a alternate to sodium chloride (NaCl) in AP. I use a 50/50 mix of KCl/NaCl in my system.

To answer your first question, YES its going to be a problem if you are consistently topping off with soften water because as your water is either uptaking by the plants or is evaporated the KCl is going to remain in the system. The minerals are to heavy to be evaporated out of the water. So if you continue to add water with KCl your gonna have a build up of salts in the system. You wanna keep your system at .1ppt for general tonic or .3-5ppt for medicating the fish for diseases.

Your Ph with stabilize once your acids neutralize all the carbonates in your water.  Then the nitrification process will start to lower your Ph naturally and your gonna have to add carbonates to your system to get the Ph from dropping to low. I would stop the use of Ph down because its Phosphoric acid which is an antibacterial, and we don't want that hurting our bacteria colony. I'm not 100% positive about it being antibacterial, just remember read somewhere it was. I would use hydrochloric acid (HCl) instead. It can be found as a pool chemical to lower the Ph in pools. I got mine from Ace Hardware.

I've seen the same "sugar" build up on some of my plants and the conclusion of mineral build up is what I've come up with also, I'm unsure to what it is exactly.

Again please let someone else with more experience answer your questions before taking my advice because I dont want to tell you something that is not true. Hopefully someone can come back up my statements.