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Technoreef2013
01/21/2014, 11:04 PM
Hey everyone. I recently used baking soda (sodium bicarbonate) and baked baking soda (sodium carbonate) to get my alkalinity back in check. When testing my display tank with my refractometer I got a reading of 1.033. The saltwater I have stored in 55 gallon drums for water changes read 1.026 (where I normally keep it, though I plan to reduce it to a target level of 1.025). I was wondering if anyone else has run into this problem? I knew there was sodium in the baking soda, but didn't expect a significant swing in SG from using it. I plan to do a 57 gallon water change with 1.0082 SG water (determined by online calculator) to get things back on track and hook up a salinity probe and module to my Apex to catch such problems earlier in the future. Thoughts?

disc1
01/21/2014, 11:43 PM
How much baking soda have you added? That's a pretty big swing. Before I did anything drastic I'd check the calibration on that refrac and look again just to make sure.

If it really is off then bring it down. I don't think it was the baking soda that caused it unless you poured a whole heaping bunch in there.

Jimmy54
01/22/2014, 04:54 AM
1.033 as apposed to 1.026 means 8 g/l extra sodium.
For a 225 gallon system it will take approx 8 kg of sodium which is part of 29 kg of Sodium bicarbonate.
That's a lot ;) I mean I would take me about 4/5 years to supplement that amount to my 225 gallon system, and I don't use a calcium reactor ;))

So yes, maybe better check your refractometer.

Jimmy

Jimmy54
01/22/2014, 05:37 AM
But than again; I've been reading some of your other posts.
It seems you have had, or still have, pH and alkalinity problems, which I by the way don't really see.
So for how long are you adding sodium bicarbonates, and how much?

Also the effluent from your calcium reactor seems to be too low with dkh 10,6, maybe you're adding CaCl too?

Jimmy

Technoreef2013
01/22/2014, 08:43 AM
Thanks for the replies. Jimmy, that is a lot of baking soda! I did make a significant correction (14.4 g sodium bicarbonate) a few days to get my alkalinity to 10.6, but not several kilos worth :) ! I'm also running a Ca Rx which is currently holding alkalinity stable at 10.6 dKH. I've subsequently started dosing B -ionic ESV part two to get my calcium levels up. I measured it recently at 360 ppm, which is definitely low. My pH problem has been resolved with running my skimmer airline outside and through a soda lime CO2 scrubber. It's at 8.22 and pretty stable, with a small drop at night. I have 0 phodphates, nitrates, nitrites. My magnesium is 1440 as measured by a Salifert kit. I got my SG down to 1.027 with a water change and plan to lower the salinity gradually with my Liter Meter water exchange system (4 gallon change per day). I do plan on checking the calibration on the Liter Meter to ensure it's pumping out the same amount of water it is pumping into the sump. I figure the salinity probe will be a good redundancy/check.

dkeller_nc
01/22/2014, 08:52 AM
I got my SG down to 1.027 with a water change and plan to lower the salinity gradually with my Liter Meter water exchange system (4 gallon change per day). I do plan on checking the calibration on the Liter Meter to ensure it's pumping out the same amount of water it is pumping into the sump. I figure the salinity probe will be a good redundancy/check.

This is likely the source of your issue. The Achilles heel of any automatic water change system is precisely balancing the flows coming in or going out. It really doesn't take long at all for a malfunctioning or incorrectly set-up AWCS to drastically swing the salinity of a tank up or down.

Technoreef2013
01/22/2014, 09:06 AM
Dkeller. I think your right, but admittedly I haven't been as diligent as I should have been at checking the salinity of my mixed saltwater with the refractometer. I just filled one of my drums to replace depleted water (I did know the amount from carefully marking the drum) and added the appropriate amount of salt mix for the water) and after it was mixed overnight filled my water exchange drum water. I'll be more vigilant on the salinity in my water in the future, but also regularly calibrate my Litermeter. The only other thing I can think of is my ATO (Litermeter UPLC II) not replacing evaporated water appropriately, but the level in the sump looks pretty steady. I add kalkwasser to a kalk Rx and use it for top off.

bertoni
01/22/2014, 02:53 PM
I would lower the SG over a period of days or maybe a week or so. Sudden SG changes can be stressful for animals. It'd take a very large amount of baking soda to raise the SG that much, which implies a very long time frame, likely months, for that large a rise.