Water Change Drum High Alk and High Calcium

[CSS Reef]

Anyone have experience with Reef Crystals mixing with high Alk and high Cal??

My tank parameters

Ammonia - 0
Nitrite - 0
Nitrate - undectable
SG - 32 ppt
Alk - 11.3
Cal - 420
Magnesium - ? test kit on order


Anyway, I am trying to mix 30 gallons of Reef Crystals for a water change at about 39ppt in an attempt to slightly raise my salinty to 35 ppt (from 32 ppt). I tested my tank paramters and came up with acceptable numbers above.

However, when I went to test my 30 galon drum of Reef Crytals my ALK and CAL were of the charts (Salifert test kit) approx guessing 17DKH for alk and 500 for calcium. I have not added any supplementation like 2 part etc.. to the bin?? It is all mixed with RO/DI that tested 0 TDS and had been mixing with a powerhead and heater for 48 hours.

Can this be a bad batch of salt? Just need to see if anyone has gone through this with Reef Crytals. Also, is there anyway ot correct this. I dont want to throw out all 30 gallons.....

By the way this is my first time using Reef Crystals. I have always used IO in the past and corrected with 2 part.

[Icefire]

High Salinity = higher Ca/Mg/Alk/etc..

lets say 420Ca @ 32ppt = 511 Ca @ 39ppt

[bertoni]

I agree. The numbers seem reasonable to me, given the high salinity.

[Billybeau1]

I suspect whatever you use to check specific gravity is off.

First off, Reef Crystals @ 35 ppt (1.0265) is 420 ppm.

So if you mixed to 39 ppt, that would be 4 points higher.

420 div by 35 is 12 ppm per ppt.

4 x 12 is 48ppm or 468 ppm of calcium.

Alkalinity does not seem to respond to the normal ratios like calcium and magnesium because of other factors. Like pH etc.

How do you measure salinity ?

[CSS Reef]

I dumped some water to lower salinity and topped off with RO/DI. The drum is now 1.024 with Calcium at 460 but ALK is 15.7 DKH? I am using a refractometer to measure.

[Billybeau1]

Alk still seems a little high. I'd still use it. '

Since your tanks alk is 11, I doubt it will raise more than a point with that water change.

When is the last time you calibrated your refract ?

[CSS Reef]

Just calibrated with DI. All worked out I went aherad with the water change and my parameters ended up being 12 DKH and Calcium was 440.

[marsh]

You need to calibrate with a known saline solution such PinPoint 53 mS fluid..not RO/DI

[CSS Reef]

Can you tell me more about this solution? Is it a fixed sepcific gravity the I calibrate the refractometer to match? Where is the best place to buy? Thanks.

[marsh]

This solution has a refractive index equal to seawater. Other simular fluids with the same 53 mS conductivity may not have the same refractive index. For example a 53 mS solution of KCL will not have the same refractive index as seawater at 53 mS. Just happens the way they make the PinPoint 53 mS calibration fluid that the refractive index is the same as seawater. Same argument goes for RO/DI water...refractive index is not the same as seawater.
It all leads to calibration errors and therefore subsequent measurement errors.

You can buy it through many of the sponsors of RC.

[Billybeau1]

You'll want the Pinpoint 53ms calibration fluid. I think I bought mine at fishsupply.com