alkalinity help

[bonez]

My tank 140 gal is low in Alk 6 DKH not to explain all the problem and things I have tried to fix it I started from square 1. I mixed a gallon of RODI water and salt, I have done this with different salts in different gallons. 1.025 salinity 1400-1500 Mag, Alk 6.5-7 Dkh , 320 calcium from the mix. I added soda ash to raise the alk to 9 Dkh as in my aquarium the Alk falls in about 3 hours to 6.5-7 Dkh. This water is in a jug not in the aquarium so why? This method rules out aquarium problems, what could be bad, Water, soda ash?

[disc1]

precipitation?

[ali1]

I would think you need to use both in the tank .. alk and calcium to elevate levels

If your only dosing one or the other, your going to get skewed results.

Also, i would doublecheck with another test kit to eliminate a faulty one

[bertoni]

I'd try baking soda, which leaves the pH mostly unchanged, and see whether that helps. Soda ash increases the pH, which can encourage precipitation.

[mattgreene22]

Is your Magnesium low? If I remember correctly the Magnesium helps keep the level of available saturation up for CA and ALK

[hilgert]

Is your Magnesium low? If I remember correctly the Magnesium helps keep the level of available saturation up for CA and ALK

His Mg in the mixed saltwater was high if anything...

[hilgert]

My tank 140 gal is low in Alk 6 DKH not to explain all the problem and things I have tried to fix it I started from square 1. I mixed a gallon of RODI water and salt, I have done this with different salts in different gallons. 1.025 salinity 1400-1500 Mag, Alk 6.5-7 Dkh , 320 calcium from the mix. I added soda ash to raise the alk to 9 Dkh as in my aquarium the Alk falls in about 3 hours to 6.5-7 Dkh. This water is in a jug not in the aquarium so why? This method rules out aquarium problems, what could be bad, Water, soda ash?

What test kit(s) are you using? Have you cross-tested with other kits (from your LFS or other reefers in the area)?

Is your RODI good (probably has nothing to do with it, but...)?

What salt are you using (the Mg level seems honkin' high as compared to Alk and Ca)?

[Jimmy54]

1.025 salinity 1400-1500 Mag, Alk 6.5-7 Dkh , 320 calcium from the mix. I added soda ash to raise the alk to 9 Dkh as in my aquarium the Alk falls in about 3 hours to 6.5-7 Dkh. This water is in a jug not in the aquarium so why? This method rules out aquarium problems, what could be bad, Water, soda ash?

Maybe adding too much too fast? Especially when it comes to carbonates.
Usually it takes about 12 hours to raise dkh by 1 point in my tank using bicarbonate,
it doesn't raise pH like carbonate does :rolleyes: which is probably the reason why the alk is falling back within a few hours.

Jimmy.