Problem with Seachem Equilibrium

[Cultiver]

I have been using your products and doing some tests over the past few weeks. I have found that using Seachem Equilibrium to raise GH after doing a 40% water change using RO/DI water will progressively raise potassium levels higher and higher each week it is being used.

I am using a LaMotte freshwater GH test kit and a LaMotte Potassium test kit. Lamotte's Potassium test uses a sample diluted with RO/DI water to measure potassium levels up to 50 ppm. The GH test is a EDTA chelation test that reacts equally to calcium and magnesium ions. It does not react to potassium ions.

To repeat my test, set up a planted tank, and do a 40% water change after a week, replacing with RO/DI water. Raise GH to back to whatever it was before the water change using the LaMotte GH test and Seachem Equilibrium. Wait a few hours and do the potassium test. Repeat once per week. After only the second week, potassium levels will be shown to be higher than they were after the first week's water change. Usually after the third or forth week (depending on how high you are raising GH), the potassium readings will be out of the test kit's range.

In conclusion, Equilibrium adds so much potassium at the same time it raises the ca/mg GH, that if you maintain the *same* ca/mg GH by using Equilibrium after each water change, you will progressively raise potassium levels until they are dangerously high.

I recommend lowering or eliminating the potassium content in Equilibrium, and raising the potassium content in Seachem Potassium so Potassium can be dosed separately.

[Kostspieliger Behalter]

This logic seems very flawed to me. I don't doubt your test results (LaMotte kits are very good) but to me it is apparent *something* else is going on.

Here's what I mean...

Say you start a tank and fill it with RO water, then use Equilibrium to raise GH. If you raise GH to 6 dGH using Equilibrium, your K will end up being around 80.

Now let's say you do a water change. You take 40% of the old water out, then replace with new water. If you reconstitute the new water with Equilibrium to 6 dGH / 80 ppm K, then add this back to the tank, the tank water will STILL be 6 dGH / 80 ppm K.

Again I am not doubting your test results... but your K raising drastically after only two or three water changes just doesn't sound plausible unless there is some other factor(s) involved.

Besides, if you raise GH to 6 dGH with Equilibrium you are already off the scope of the LaMotte test kit.

I do agree however that the user should have control over K dosing... ideally it should be 20 ppm. There are numerous reports (note that this is basically conjecture, I haven't read anything scientific) that increasing K to VERY high amounts (several hundred ppm) in water that has >20 ppm of CO2 can cause "calcium uptake" problems... probably referring to the weakening of established plant leaves. Anyway, if I want to raise my GH to say 10 dGH but have my K between 20-30 ppm, this is not possible with Equilibrium. Personally I use Greg Watson ferts to raise GH (CaCl2 and MgSO4) and K (K2SO4), but would rather use Equilibrium, if only it didn't contain all that K!! :)

[Tech Support RB]

I understand your point and if you wish to maintain a lower potassium level with an increased GH, you can use part Equilibrium with some of our Reef Calcium. I find that planted aquarium hobbyists often go for our Reef Calcium product when looking to increase calcium levels.

We will also be coming out with a liquid GH product to do just what you are looking for and will be an excellent compliment to our Equilibrium and the rest of our planted aquarium line. It should be out in the next few months. Until then, either your method or my suggestion mentioned above should help.

[dc88]

I think Cultiver's finding can be a valid one.
Consider this :
- He added Seachem Equilibrium to the tank water to reach 6 dH
- A week later he did a 40% water change and he added Equilibrium to the total tank water (notice that he did not say adjusting just the replacement water) so that the total tank water reach 6dH again.
- He repeated it for another week, and then found that the K level pepertually increased.
- Why the potassium level increase while Ca/Mg total gave 6 dH ? One possibility could be that the Ca in the tank water had precipitated over the week - a likely scenario if the CO2 level is not adequate. Some plants can extract CO2 from the HCO3- in the water can offset the Ca++ buffering balance which cause Ca++ to precipitate as CaCO3, If this happens, then there will be lesser Ca in the water but as CO2 is inadequate the plants may consume lesser potassium, hence the water in the tank would have more potassium than calcium. And when he made a 40% water change and added back Seachem Equilibrium to get the desired total GH level (according to the GH reading which is indication of Ca+Mg) the resulting effect would be the accumulation of potassium.

BTW I hope to see the liquid GH+ product (without potassium) from Seachem soon as it will allow more flexibility for us to adjust the tank water parameter, I have not seen it in our local shop yet.

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