Kent osmo-prep

[revance]

I just recently setup a reef tank (just live rock at the moment... still cycling). However I have had a lot of trouble maintaining a proper alk/pH. Even newly mixed water (I use RO/DI water with Oceanic salt) has a very low Alk (1.5-2.0 meq/L) and pH (7.9). I have tried aerating the RO/DI water before adding salt, and I always wait a day before using the water. My calcium levels are pretty good (usually around 425), not high enough to prevent establishing a proper alkalinity (is it?).

It seems to me that the alkalinity is being used up buffering the unstable ro/di water. Would it be a good idea for me to use something like Kent osmo-prep to buffer the RO/DI water before adding the salt mix?

I have tried correcting with B-Ionic 2 part (only using the alk part), but since it is already out of whack, I think I am fighting a loosing battle (especially since the tank is cycling). I think I really need to focus on getting my mix right, then things can even out through some water changes. Any help is appreciated!

[revance]

Ok, I found an older thread on a similar subject. It suggests that the "pre-salt" additives don't really do anything. Any other ideas as to why newly mixed water would have such a low alkalinity? Could the magnesium levels be off? If so, could I have just gotten a bad batch of salt? Again, any suggestions are appreciated!

[Randy Holmes-Farley]

I do not know why the Oceanic might have low alkalinity. Some folks have reported unusually high calcium in some Oceanic batches, and perhaps you had that too, which later precipitated a bit of CaCO3. The RO/DI water isn't the cause, and as you found, Osmo Prep isn't the answer.

If you are confident in the alkalinity test kit, then a little baking soda can be used to raise the alkalinity.

From this article:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm


"To raise 50 gallons of tank water by 1 meq/L will require about 16 grams of baking soda (sodium bicarbonate; sodium hydrogencarbonate). Since a level teaspoon of baking soda weighs just under 6 grams, then 1 teaspoon will raise the alkalinity in that 50 gallons by ~0.4 meq/L (~1 dKH)"

[revance]

I have tried using baking/washing soda to raise the alkalinity, and have also tried B-Ionic (only the alk part), but it just seems to fall right back down within a few hours. I have let it be for a couple days and it seems to have stabilized with a pH of 7.9. I am going to test the alkalinity and calcium levels when I get home today and I will post those findings.

I think I am going to switch my brand of salt. I kind of expect newly mixed water to have correct parameters. It is much easier to start with well balanced water and keep it that way, rather than start with messed up water and spend all my time trying to keep it in check. I think when I first mixed the water I had a calcium level of 450 mg/L and an alk of 1.5 meq/L... seems pretty messed up to me. I will double check these numbers.

I will post new information as soon as I get it. Thanks!

[Randy Holmes-Farley]

I wouldn't use B-ionic or washing soda to raise the alkalinity in a situation like this as that will push the pH too high. Baking soda is the ticket.

If the alkalinity falls in a container of artificial salt water, then either the calcium, alkalinity, or pH is too high, or magnesium is way too low.

[revance]

Somebody on another forum said that they have also experienced high calcium and low alk levels with oceanic and experienced the opposite with Instant Ocean. They were thinking of mixing the two salts 50/50 to see if they could achieve a happy medium... anybody try this or have an opinion on it?

Thanks for the heads up on the baking soda!

[Randy Holmes-Farley]

I use IO and have had no troubles with it alone.

Mixing is fine if the parameters seem better for the particular batches that you are using.