Strange Starting Parameters on New Tank?

Chris918 · 08/19/2016, 11:57 AM

Hey guys.

If this would be better answered in the "New to the hobby" section please let me know and I will move it. This is about the chemistry of my tank however.

Currently the tank is empty. The tank has been set up for several months. I am at the point where I believe it is fully cycled and the rock fully cured. I plan to have this be my first tank with corals and I have my two part from BRS ready for dosing, but I am getting some unexpected pre-dose results from my Red Sea kit.

Results:
Ca: 485 ppm
Alkalinity: 13.4 dKH
Mg: 1240 ppm

Further tests: (API)
Ammonia/Ammonium: 0 ppm
Nitrite: 0 ppm
Nitrate: 5-10 ppm
pH: 7.9

Specific Gravity: 1.025
Temperature: Constant 78 degrees.

I use Instant Ocean salt mix (not reef crystals),
This tank's water was set up with an RO system with a newly installed DI Resin, but I wasn't getting down to 0 TDS. It was closer to 5-7, which I also saw as strange. I let it run for 2 hours to get this reading and the system was less than a month old, but I admit it was cheap. I have since replaced it with BRS 150 GPD 6 stage RO/DI and I get 0 TDS on that every time and love it.
The tank was started with live sand, pukani rock, and some additional dry rock from a LFS.

So what do you guys recommend? Does this seem strange to you? I thought such a high alkalinity would mean a high pH. I have also never dosed the tank so unless the salt mix has all these elements in it I am at a loss for that and such high readings.

Should I do a total water change with the brand new 0 TDS RO/DI water, wait a week and then test again?

I greatly appreciate your guys' time in reading this and I look forward to any advice you have for me.

Thanks!

Chris

vhuang168 · 08/19/2016, 12:12 PM

I would calibrate the refractometer to make sure you are actually at 1.025. A higher SG will account for the higher levels of alk n ca.

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Chris918 · 08/19/2016, 12:20 PM

The refractometer is only 2 months old. Would it really need to be calibrated already? Seems so soon. Still I'm not crazy for thinking these levels are abnormal it seems lol

vhuang168 · 08/19/2016, 12:22 PM

You should have calibrated before you even used it the 1st time.

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Chris918 · 08/19/2016, 12:24 PM

I certainly did. I calibrated it with the solution that came with it. I have a hydrometer that's fairly new I could get a second reading with that I suppose. Have to wait until I'm home unfortunately.

bertoni · 08/19/2016, 07:07 PM

Sometimes, batches of salt products seem to be a bit off, and sometimes the salt settles badly during shipment. Those numbers are a bit strange, but they should be safe enough. You could try mixing the dry salt a bit before making any more saltwater, but it might not help.

Chris918 · 08/20/2016, 09:51 PM

Okay hopefully all is okay. I did a 90% change with my new RODI machine's water and that will get rid of the nitrates too I'll test in a few days and see what I get.

08/19/2016, 11:57 AM	#1
Chris918 Registered Member Join Date: Jul 2016 Posts: 174	Strange Starting Parameters on New Tank? Hey guys. If this would be better answered in the "New to the hobby" section please let me know and I will move it. This is about the chemistry of my tank however. Currently the tank is empty. The tank has been set up for several months. I am at the point where I believe it is fully cycled and the rock fully cured. I plan to have this be my first tank with corals and I have my two part from BRS ready for dosing, but I am getting some unexpected pre-dose results from my Red Sea kit. Results: Ca: 485 ppm Alkalinity: 13.4 dKH Mg: 1240 ppm Further tests: (API) Ammonia/Ammonium: 0 ppm Nitrite: 0 ppm Nitrate: 5-10 ppm pH: 7.9 Specific Gravity: 1.025 Temperature: Constant 78 degrees. I use Instant Ocean salt mix (not reef crystals), This tank's water was set up with an RO system with a newly installed DI Resin, but I wasn't getting down to 0 TDS. It was closer to 5-7, which I also saw as strange. I let it run for 2 hours to get this reading and the system was less than a month old, but I admit it was cheap. I have since replaced it with BRS 150 GPD 6 stage RO/DI and I get 0 TDS on that every time and love it. The tank was started with live sand, pukani rock, and some additional dry rock from a LFS. So what do you guys recommend? Does this seem strange to you? I thought such a high alkalinity would mean a high pH. I have also never dosed the tank so unless the salt mix has all these elements in it I am at a loss for that and such high readings. Should I do a total water change with the brand new 0 TDS RO/DI water, wait a week and then test again? I greatly appreciate your guys' time in reading this and I look forward to any advice you have for me. Thanks! Chris

08/19/2016, 12:12 PM	#2
vhuang168 Registered Member Join Date: Feb 2015 Location: San Jose, CA Posts: 2,136	I would calibrate the refractometer to make sure you are actually at 1.025. A higher SG will account for the higher levels of alk n ca. Sent from my iPhone using Tapatalk __________________ Vincent 40g custom AIO --> DSA190Pro

08/19/2016, 12:22 PM	#4
vhuang168 Registered Member Join Date: Feb 2015 Location: San Jose, CA Posts: 2,136	You should have calibrated before you even used it the 1st time. Sent from my iPhone using Tapatalk __________________ Vincent 40g custom AIO --> DSA190Pro

08/19/2016, 07:07 PM	#6
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	Sometimes, batches of salt products seem to be a bit off, and sometimes the salt settles badly during shipment. Those numbers are a bit strange, but they should be safe enough. You could try mixing the dry salt a bit before making any more saltwater, but it might not help. __________________ Jonathan Bertoni

08/19/2016, 12:20 PM	#3
Chris918 Registered Member Join Date: Jul 2016 Posts: 174	The refractometer is only 2 months old. Would it really need to be calibrated already? Seems so soon. Still I'm not crazy for thinking these levels are abnormal it seems lol

08/19/2016, 12:24 PM	#5
Chris918 Registered Member Join Date: Jul 2016 Posts: 174	I certainly did. I calibrated it with the solution that came with it. I have a hydrometer that's fairly new I could get a second reading with that I suppose. Have to wait until I'm home unfortunately.

08/20/2016, 09:51 PM	#7
Chris918 Registered Member Join Date: Jul 2016 Posts: 174	Okay hopefully all is okay. I did a 90% change with my new RODI machine's water and that will get rid of the nitrates too I'll test in a few days and see what I get.