My water supply has low KH

[Sgolden]

I run a sps / mixed reef. 7 stage to/do. My fresh water after filter is testing 4kh. Our local municipal uses well water .
after mix with Red Sea blue bucket , I have to add Kent super buff dkh.
This is a recent found issue. My auto water top off comes from the same source. Meaning it must be compensated . Otherwise , I’m afraid of my kh not stable enough.
I am manually dosing b- ionic and kend super buff to maintain all.

open to suggestions. Anyone else battle this ? I know that a lot of municipal wells have seasonal ph changes.

 

[Copingwithpods]

Doesn't really matter what your freshwater is at, once mixed with let's say redsea blue bucket you'll be at 9dkh. You don't need to add any buffers unless you are shooting for a higher dkh

 

[andrewey]

I've never worried about the alkalinity of my source water. My top off volume doesn't impact my alkalinity in any meaningful way and my alkalinity after mixing with salt is as high as I need before daily dosing.

 

[LxHowler]

Surely the top off water shouldn't matter too much as you are only replacing the evaporated water, you will only dilute your kh back to what it was before the evaporation? You should surely only need to use the buffer at the start to boost your dkh to your desired level and then dosing to maintain what is used by corals.

 

[Copingwithpods]

You do not want alkalinity in your tap water for top off, and I do not recommend tap water at all.

I think you misunderstood, he/she is worried about the kh reading of the rodi water.

 

[Randy Holmes-Farley Verified Community Expert]

I think you misunderstood, he/she is worried about the kh reading of the rodi water.

Sorry, yes, i see now. The original post doesn't actually make any sense to me.

 

[Randy Holmes-Farley Verified Community Expert]

I run a sps / mixed reef. 7 stage to/do. My fresh water after filter is testing 4kh. Our local municipal uses well water .
after mix with Red Sea blue bucket , I have to add Kent super buff dkh.
This is a recent found issue. My auto water top off comes from the same source. Meaning it must be compensated . Otherwise , I’m afraid of my kh not stable enough.
I am manually dosing b- ionic and kend super buff to maintain all.

open to suggestions. Anyone else battle this ? I know that a lot of municipal wells have seasonal ph changes.

Let's back up.

The RO./DI water reads 4 dKH before you added anything?

What are you adding buffer to and why?

If the RO/DI reads 4 dKH, I expect the kit may be wrong, or maybe the DI is shot. Must be one or the other.

An RO alone will with no DI will not have 4 dKH in it.

A newly depleting DI might possibly have 4 dKH in it from bicarbonate coming out of the DI, but I think that is less likely than a kit error.

 

[Sgolden]

Let's back up.

The RO./DI water reads 4 dKH before you added anything?

What are you adding buffer to and why?

If the RO/DI reads 4 dKH, I expect the kit may be wrong, or maybe the DI is shot. Must be one or the other.

An RO alone will with no DI will not have 4 dKH in it.

A newly depleting DI might possibly have 4 dKH in it from bicarbonate coming out of the DI, but I think that is less likely than a kit error.

4dkh prior to mixing salt. After it goes through the filter . After I mix Red Sea blue box , it reads 7dkh.

 

[Deezill]

4dkh prior to mixing salt. After it goes through the filter . After I mix Red Sea blue box , it reads 7dkh.

Do one of a couple things. I have never seen folks worry about the dkh of source water to each their own. Use a salt that mixes at higher dkh and dose until you get to the desired level. if you want to continue to use the blue bucket and its only 7 dkh get some 2 part from BRS or another vendor.
You can dose until you are happy.

 

[Sgolden]

I am having to add buffer to get it to 9 alk. This before I do a water change, after salt has been mixed.
Also, if I’m adding make up water with low alk, I’m guessing it prematurely lowers my tank kh. Meaning I’m dosing more frequent to keep up.
Please correct, ro/di do not effect ph/all? Thought it removes solids, chems, hardness.

 

[Deezill]

Im confused you increase the alk and then do a water change?

 

[Deezill]

After you do a water change check you parameters then slowly increase the alk if its not at 9.
only raise it by 1dkh per day.

 

[Copingwithpods]

To what Salinity do you mix your salt?

 

[Sgolden]

Let me back up. I fill my storage with fresh water out of my ro/di. Before adding salt, it reads 4kdh. I only did it because after mixing salt ,dkh reading was at 7.
I have not tested this prior to today.
I added buffer just today to the mixed water reading 7kdh. Because my tank reads 9 . Should I not worry? Ithought in a water change, to have incomming parameters as close to tank as possible .

 

[Sgolden]

My system has been up for 4 years. I know what my tank numbers need to be. Keeping them there is another issue. Trying to keep on topic. But, I know the experts need to ask the questions. I replaced filter cartridges 2 months ago. If my freshly mixed water is reading 7kdh prior to adding to tank, do I adjust prior with a buff ? Or adjust after it’s in the tank .
I have a total of 260gallons in the system, I replace 40 gallons at a time. But, I don’t water change frequent. Battled some cyano and dosed with chemiclean. Doing a double water change to neutralize effect , followed by carbon.

 

[Copingwithpods]

Let me back up. I fill my storage with fresh water out of my ro/di. Before adding salt, it reads 4kdh. I only did it because after mixing salt ,dkh reading was at 7.
I have not tested this prior to today.
I added buffer just today to the mixed water reading 7kdh. Because my tank reads 9 . Should I not worry? Ithought in a water change, to have incomming parameters as close to tank as possible .

At what specific gravity or ppt are you mixing it to, blue bucket mixes to 7/7.5 and 8 per instructions.

Also a possibility although extremely rare is you got a bad batch of salt.

 

[Sgolden]

Mix to 1.025. Maybe I’m overthinking . And will look at a different salt medium .

 

[Copingwithpods]

At 1.025 that salt will mix in the 7s so yes if you want 9s you'll have to dose.

I mix mine to 1.026-27 roughly 35ppt (roughly 8dkh) and before each water change I dose it up to 9 dkh and 440cal using 2 part

 

[Sgolden]

Thanks for the responses, I should have worded it better up front .

 

[Copingwithpods]

Thanks for the responses, I should have worded it better up front .

No problem, bet yeah don't worry about your rodi waters dkh, I use filtered water for my top offs and mixing, just checked it and it's 4dkh and I've never had an issue with dosing or my salt mix not mixing to correct values. If you want bump your Salinity up a tad to get you closer to 8dkh so you only buff up 1dkh.