KH is at zero!

[MikeKoh]

I just tested my KH with Sera KH test kit. According to the instruction, the 1st drop will change the water to blue...and subsequent drops will change the solution to yellow via green. But at my 1st drop, the solution is starting to become yellow.... never saw it turn to blue!

Does this mean that my water KH is 0! I tried in on tap water...also same result.

I have coral chip in my tank. My current PH is 7.3.

How do I up my KH?

[stressed]

Hi,

Just to share my experience though it may not be directly helpful to your post.

I have the same test kit as you do, never had this phenomenon you experienced. Mine always 1st drop turns to BLUE, however there were couple of times I tried the 2nd drop, half the normal drop size haha....and it also turned to yellow, so also abit subjective, KH about 1.5??

I have also tried adding another drop even after solution is yellow, and the solution turns dark yellow and no subsequent addition of the reagent will change the colour of the solution, so can I conclude that this is the way to go? Drop till colour does not change which is a deep yellow.

[vinz]

Drop until the solution turns yellow. Sometimes, it goes from blue straight to yellow, sometimes to green first. If it goes green first, I assume it to be 0.5, but I count as 1 anyway. No need to be that accurate.

Mike, did you shake a little to mix the solution after each drop? If you did, then yes your KH is 0 or 1. If not, try again.

What else do you add to the tank? Any water conditioners (like pH-down), blackwater, driftwood, ketapang leaves, etc?

[bclee]

...or you can double the volume of the water sample. E.g. use 10ml insteal of 5ml. Divide the no. of drops by 2.

BC

[eric_thian]

you mean........blackwater also can reduce KH[:0]

[bubbly]

Hmm...I have the same problem. I use Sera Peat Granules in my canister filter. I tried using KH Plus, but everytime I add enough to increase KH by 2, the next day, the KH either goes back to 0 or 1. Could it be the peat that's causing the KH to drop?[]

[bubbly]

Just read the other thread about using baking soda. Will try that.

[bclee]

Yes, peat and blackwater reduces KH.

BC

[HantuAir]

I have the same problem with Aquamedi KH test kit .... after 2 drops, the colour become urine kind of yellow (no better comparisonlah) never turn blue or green ... summore 6 rummies died. PH at 6 ... temp 26deg cel. What the heck happened???? So how to calculate KH? 1? 2? or 0? Will adding baking soda help clear this problem?

[bclee]

If turn yellow at the first drop, KH will be 1 or less.

BC

[sherchoo]

Waterghost,
If your test kit is showing yellow after 2 drops, then it should be 2dkH. Assuming that this is true, your CO2 level is about 60ppm which is probably wat's killing your fish.

[stressed]

why are pple looking to reduce kH? thought they would be more keen to reduce pH through peat and increase kH through baking soda?

always tot that higher kH is better to reduce pH swings... please advise

[vinz]

Not exactly. As long as you have 1 KH, it will buffer the pH swing. Higher KH does not buffer the pH swing better then 1 KH. However, higher KH raises the pH.

In other words, for the same ppm of CO2 in the water, the pH will drop by the same amount as long as you have at least 1 KH. The diff is that the starting pH is higher if the kH is higher.

Another important thing to note: I said ppm of CO2 in the water, not amount of CO2 injected. At higher KH, you need to inject more CO2 gas to get the same ppm of CO2 dissolved in the water.

[vinz]

Oh yah, some ppl who hasn't seen the Sera KH kit turn blue will probably wonder HOW blue it should be. The first drop will be very obviously blue if you have at least 2 or 3 dKH. Not green-blue, or yellow blue. It's deep sky blue.

[HantuAir]

Wahlaueh (What the hell!) ... so cheeme (complex)!!! ... So I need to up KH so that the CO2 will be better dissolved or taken up by plant. Rite? Anyway thumbs up to Vinz & Serchoo & bclee ... slowly trying to understand all this science stuff ... today rummy looks ok ... no mo casualties ... so I refer to chart I guess ... any good resources?

[vinz]

Wrong... KH does not improve CO2 dissolution nor plant uptake.

If you have zero KH, when you inject CO2, your pH will drop very low. You need at least 1 KH to BUFFER the pH change. Meaning, it will reduce the drop of pH.

Increasing KH also increases your pH. So say X ppm of CO2 cause your pH to drop by P. Assuming at 1 KH, before injecting CO2, your pH is P1. If you maintain X ppm of CO2, your new pH will be (P1 - P).

Now say you raise for KH to 4 which causes your new pH to rise to P2 before CO2 injection. With X ppm of CO2, the pH will be (P2 - P).

Hope you get it now. Now go read Chuck Gadd's article and chart. www.thekrib.com has good info too.