Aquarium Chemistry Question? Ask the Doctor!

[Chiefmaster30]

It's a fine thing to try. The primary drawback is the organic carbon dosing of the vinegar which may reduce nutrients more than you want (or not).

That said, I think organic carbon dosing has benefits beyond nutrient reduction, such as the bacteria providing food for many organisms.

Increasing the potency by 50% (adding a third teaspoon) in 1 gallon of top off water is the same as 41.4 mL of my recipe #1 (as from BRS). So it might work if you add a gallon or close to it each day.

Thanks Randy! I add close to a gallon a day! I’ll try it! Am I correct by using 225ml of vinegar and 15 tspns of Kalk when mixing 5 gallons of top off water?

 

[Randy Holmes-Farley]

Thanks Randy! I add close to a gallon a day! I’ll try it! Am I correct by using 225ml of vinegar and 15 tspns of Kalk when mixing 5 gallons of top off water?

That sounds like a good recipe, yes.

 

[Danny Venditti]

The more often, the better. How often is 'needed" depends on the tank and how much demand (in alk dKH per day) is being dosed.

so if I am dosing 100ml a day to keep levels stable and doing 5ml 20 times a day that is fine.

 

[Randy Holmes-Farley]

so if I am dosing 100ml a day to keep levels stable and doing 5ml 20 times a day that is fine.

You are asking about calcium and alkalinity additives? That's certainly fine. Many people find most of the alk demand is during the day so they concentrate dosing between lights on and lights off

 

[Chiefmaster30]

That sounds like a good recipe, yes.

Tried the vinegar and alk still drops from 9.0 down to8.8 dkh daily!

 

[Randy Holmes-Farley]

Tried the vinegar and alk still drops from 9.0 down to8.8 dkh daily!

You might go a few days more and see where it stabilizes, or if you really want 9 dKH, then a two part is probably the way to go.

 

[Chiefmaster30]

You might go a few days more and see where it stabilizes, or if you really want 9 dKH, then a two part is probably the way to go.

So your saying I should ride it out a few more days without adding 2 part and see if it levels out with what I’ve already got in ato?

 

[Randy Holmes-Farley]

So your saying I should ride it out a few more days without adding 2 part and see if it levels out with what I’ve already got in ato?

I would. Maybe it won't drop that much more.

 

[Chiefmaster30]

I would. Maybe it won't drop that much more.

Alk dropped from 8.8 yesterday to 8.7 dkh today. Have noticed the green film I always get on my glass today is a whitish looking film. I’m guessing this is from the vinegar I added to Kalk! Is this ok? Thanks in advance!

 

[Randy Holmes-Farley]

Alk dropped from 8.8 yesterday to 8.7 dkh today. Have noticed the green film I always get on my glass today is a whitish looking film. I’m guessing this is from the vinegar I added to Kalk! Is this ok? Thanks in advance!

Sounds OK, but vinegar often causes bacteria to grow out of sight. If it becomes unsightly, switching away is probably easiest.

 

[chomoney]

Hi Randy,

I’m switching from Potassium nitrate to Sodium nitrate for my nitrate dosing.

This is the Sodium nitrate I have ordered:
Sodium Nitrate, Reagent Grade (chemically pure) – 1 lb. bag https://www.amazon.com/dp/B0190TOJUS/ref=cm_sw_r_cp_api_cThQAbG32SHCT

The calculator I use does not have an option for Sodium nitrate, unfortunately:
http://www.theplantedtank.co.uk/calculator.htm

When mixing Sodium nitrate into solution for dosing, is the calculation the same as Potassium nitrate? If not, do you have a recommendation on how to make the calculation?

Thank you!!

 

[Randy Holmes-Farley]

It is close enough that you'd never see the difference by test kit, but in theory you would use 16% less, so if it called for 1 gram of potassium nitrate, use 0.84 grams of sodium nitrate.

 

[chomoney]

It is close enough that you'd never see the difference by test kit, but in theory you would use 16% less, so if it called for 1 gram of potassium nitrate, use 0.84 grams of sodium nitrate.

Thank you for always saving the day on stuff like this!

 

[Randy Holmes-Farley]

Thank you for always saving the day on stuff like this!

lol

You're welcome.

Happy reefing.

 

[Chiefmaster30]

Sounds OK, but vinegar often causes bacteria to grow out of sight. If it becomes unsightly, switching away is probably easiest.

So after a week of using the vinegar and kalk in my ato I’ve still had to dose 27ml of 2 part to keep my alk at 9.0. My calcium is on the high side at 450 so all this week I have only dosed the 27ml of the alk part. Is this normal and ok since my weekly water changes seem to be keeping my calcium at 450.

 

[Randy Holmes-Farley]

That's fine.

 

[Blue Tang Clan]

Hey @Randy Holmes-Farley, I have a pH issue that I've been struggling with for 2 weeks now. I've read all of your (excellent!) articles on the topic and have scoured the web, but I still need a little more guidance. Here is an approximate timeline of events.

• 90G; 2016 Apex; great sump, great skimmer, great powerheads, Kessil A700 dual LEDs; corals - mostly hammers, and a few SPS frags
• Tank always goes to 8.3 during peak day, and goes no lower than 8.2 at night - this was the case all winter with glass tops and a canopy on top

• Late March - I put in 30 or so pounds of BRS pukani dry rock, which I had been treating with lanantham chloride in a Brute bucket for 6 weeks. I may have gone too heavy on that stuff, as my (first ever) Triton reading showed high Lithium. I'm no chemist, so I assume they are related. I attached the results.
• April 17 - I added a Neptune DOS, with BRS Alkalinity solution on one side, and Vodka on the other. It is very possible that I calibrated and primed the pumps too long and the vodka was overdosed into the tank.
• April 18 - Ph drops in the early morning to 8.05, which is very low for my tank
• April 19 - Ph rebounds to 8.22, bottoming at 8.15 for the next 2 days
• April 20 - 30 gal (1/3 water change) with new salt - Red Sea Coral Pro. It's got tons of extra good stuff and I thought that would solve pH issues. I also remove the canopy for the summer, and stored the glass lids. This should have solved all issues - right? More gas exchange, etc.? Nope. I ordered a new pH probe from BRS in case mine was wonky
• April 21 - Ph drops below 8.0, eventually going as low as 7.9
• April 22 - Ph can't get above 8.0 anymore; New BRS probe shows no difference, even calibrated (correctly) with multiple packets
• April 22 - I add a little dKh superbuffer to the main display tank to try to bring up the pH (I now know this was shortsighted) - and then I whip up a batch of Kalk to add more than the usual amount to the display
• April 23-26 - pH still won't go above 8 in the display. NOTE: I took a cup of the new frag tank water, which started off at 8.3 pH on day one, and it was already down to 8.09. How can my house be bringing down the pH so much? I opened up all the windows, even the one right next to my tank. There is fresh air everywhere!
• April 28: I set up a separate 10G frag tank and transfer most of the SPS there - just a light, power head, and heater. It has 10G of new saltwater so there should be no issues transferring over from the display tank.
• April 29 - I give up on finding the source of the problem and order a CO2 scrubber and media from BRS to help keep everything from dying.
• April 29 - 30 gal (1/3 water change) with Red Sea Coral Pro.
• April 30-May 3rd: pray, and occasionally dose kalk.
• May 3: Set up CO2 scrubber and the pH climbs back into a better range.
• May 8: pH has been steady, ranging from 8.08-8.13, but has no fallen back to 8.0-8.05, which likely means that the CO2 media is exhausted.

I can't believe that my tank could be solid between 8.2-8.3 for a year and then bottom out. There has to be a chemical reason, but I find it odd that a frag tank with new water also didn't hold the 8.3 pH that it started off with after a few days with the powerhead running.

Whodunnit?

1. The natural air?
2. The potential vodka overdose?
3. The pukani rock that was dipped too long in lananthum chloride?
4. The Butler?

 

[Randy Holmes-Farley]

Vodka dosing will reduce pH.

Might be the calibration was off before, if not now.

Some folks with controllers have pH measurement issues. Might be electrical interference or temp correction issues. Maybe try measuring pH in a cup of water out of the tank and maybe away from it.

Luckily, the lows now are not low enough to be a serious problem, whether real or not.

 

[Fishinwall]

Hi Randy

I’ve been trying to balance my Alk and my Ca for weeks.
My Alk right now is at 7.04 an Ca is at 550, Mg at 1335

For weeks I’ve been trying to up my Alk to about 8 and get my Ca down to acceptable levels by increasing my dosing of Alk and decreasing my Ca dosing.

I dose Core 7
Salinity is 1.025
Ph btw 8.1-8.3
Temp 78

What do you think?
Matt

 

[Randy Holmes-Farley]

I don't think 550 ppm calcium is a concern, but if you want to lower it, I'd just stop dosing calcium for a while and dose just alkalinity. A 100 ppm drop will take place during the time that about 15 dKH of alk is used, assuming you do not mess with that ratio via water changes.