To dose Baking Soda or not

[Guillaume]

Thanks for that discussion. I need to try Randy's receipe too.

Generally speaking for a reef tank, what would be considered a acceptable shift of Ph between day and night?
I have an Apex providing measurements 24/7 and knowing at any time that Ph is always shifting is tiring...
Tx

 

[Daimyo68]

I'm not having any issue in the tank, everything seems to be happy. My alk was at 8dKh, and dropped to 7, and I figured I should start thinking about dosing to, at the minimum, get back to atleast 7dKh, and then back to 8.

I am shooting for 10dKh so that I have a "Middle of the Road" levels. I guess if I can get back to 8dKh, I should just stop there so that I don't cause any other issue.

I haven't had any deposits anywhere at this point, but will continue to monitor for them. Also, I use a Kent Aquadoser to supply the Alk.

I'm going to test again tonight when I get home, all levels, and will post back results. At this point I am dripping 1 drop every 50 seconds, so just under 200ml a day.

Should I stick with the drip dosing, or start to dose in the morning and evening? I'm assuming dripping is a better road to take.

Also, when do you suggest testing? Being that I am drip dosing, I would think any time would be fine.
Thanks

 

[bertoni]

Alkalinity testing should be done at the same time each day, since it can shift significantly throughout the day. Other than that, it doesn't much matter. The drip dosing is fine.

As far as tank pH, as long as it stays in the range 7.8-8.5, the system should be okay.

 

[Daimyo68]

Ok, did a 10g WC and checked my Alk, 8dKh

***Note - I use Elos mag test kit. I was curious if the 5ml line on the syringe was correct. So I grabbed an API vial and filled it to the line. It was over. So I figured out were 5ml was in the syringe and made the adjustments in volume as needed. This obviously means that my Mag readings were off in the past few weeks since starting to use the Elos kit.

Checked all numbers the tonight:

Salinity -- 1.025
Temp -- 78.1 Degrees
pH -- 8.19 (at time of testing)
Alkalinity-- 7 dKH
Ammonia-- 0
Nitrite -- 0
Nitrate -- 0
Phosphate-- 0
Calcium -- 440 PPM
Magnesium-- 1150 PPM

So over the course of 24 hours, my dKh dropped from 8 to 7.

I am currently at 200ml of Randy's Baked Baking Soda recipe per day.

Being that my Mag is low, I am sure that this changes things. Where do i go from here? Do I keep upping my dose to get to 8dKh and then make sure my Cal and Mag are in spec?

Thanks

 

[bertoni]

I would trust the syringe more than the API vial. A lot of people have reported that the API vials are not very accurately marked.

You're dosing recipe 1 at 200 ml per day and the alkalinity still is dropping? I'll have to think about that. That seems like a lot of alkalinity.

 

[Daimyo68]

Yes to 200ml. As per Randy's instructions: After a few days of dosing, note whether alkalinity is low, high or on target. Only bother to test alkalinity, not calcium, during this period, because it is much more sensitive than calcium to over- or underdosing. Adjust the dose up or down as necessary to increase or decrease the alkalinity

My calcium seems to be ok (within range), so I am trying to get Alk to a steady level of 8dKh. Once I get there, I will watch to see where my levels go.

Maybe I am missing something. Would running a Calcium Reactor alone be a better alternative? (Asking because my buddy has a AquaMedic 1000 that he will give me).

Thanks

 

[bertoni]

Okay, I guess I'd increase the dose, but that is a fair amount of supplement. Is this the 70g system with the 29g sump?

 

[Daimyo68]

Yes on the 70/29g sump. The sump holds approx 20g total. Will let you know the results. Thanks for the responses.

 

[bertoni]

Hmm, I'd probably start taking apart the pumps one at a time, just to be sure they are free from calcium carbonate deposits. The amount of alkalinity is believable, but it's high. Coralline can consume a lot of calcium and alkalinity, though.

 

[Daimyo68]

Just cleaned the pumps etc before I changed the water and all is clear, no buildup.

I checked again tonight and I am steady at 7. Never seen it drop below this. Not sure how it is staying steady at 7 though. Coralline is growing but not at an alarming rate. I would think if it was the coralline, I would have had to scrape it off already. One thought, is it possible that the Halimeda in the sump is taking up the bulk of the alkalinity? It does do well, and sadly this just popped into my mind. But it still doesn't make sense that I can hang at 7 even dosing 200ml per day.

I think I will take a water sample to the LFS and have everything checked again Just to confirm my numbers.

 

[Billybeau1]

I realize the mark on the API vials is not correct, but I have found that using the line provided by API gives accurate results comparable to other test kits. I recommend always using the line provided on any API test kit.

One must remember that API is giving readings in 1 dkh increments so you could be 1 dkh on one side or the other with test noise.

Close enough for our purposes IMO.

 

[Billybeau1]

Are you dosing baking soda per the Reef Chemicals calculator and if so, are you figuring total water volume or just tank size ? Big difference.

 

[Daimyo68]

Further back in this thread, I had the calculator dosage, which would have been ~77ml per day once at 10dKh.

I am dosing using total system volume, not just the DT.

As for the vials and syringe: Elos Mag test (where the syringe is from) calls for 3ml of SW for each part of the test. Being that the API vials are marked at 5ml, I thought I would see how accurate the syringe was at 5ml. So what I did was fill the syringe to the 5ml mark with SW, and then emptied into an API vial to the mark. Surprisingly, the syringe holds more than 5ml at the mark on the syringe that I used.

It has 3 areas that can be considered "marks" (where the seal is at the line). I found that the upper most sealing ring is the 5ml, which in turn, puts the other marks below the 5ml mark, that I was using all along.

Makeshift diagram:

Top of syringe

----- 5ml
-----
----- What I thought was 5ml

Bottom of syringe

 

[bertoni]

I would use the kit according to the instructions, and not try to judge the accuracy of the syringe using the API vial.

 

[Daimyo68]

Sry I didn't get a chance to follow up here.

A few posts back up in this thread, I mentioned the possibility of the Halimeda eating up the Alk. Well, over the last week, I had to trim it back as it was starting to outgrow the refugium. Total, I removed about 30-35% of what I had in there. I also performed a 10g WC on June 5th.

Within a few days, my Alk started to rise, and is at this point at 10dKh for 5 days now (Dosing 200ml Baked Baking Soda per day). My pH also went up accordingly, and actually hit 8.42 this evening, with lows after lights out down to 8.14pH (Apex Log).

I changed nothing else except for the removal of some Halimeda. (Which I could still stand to remove a bit more).

I checked all other parameters also:
Salinity -- 1.026
Temp -- 79 Degrees
pH -- 8.42
Alkalinity-- 10 dKH
Ammonia-- 0
Nitrite -- 0
Nitrate -- 0
Phosphate-- 0
Calcium -- 460 PPM
Magnesium-- 1400 PPM

So over the next few days, I will watch the numbers and see what happens. I think I may need to back off the ml per day just a little so that my pH isn't going so high.

Any opinions on the Halimeda/Alk connection? I know it enjoys the Alkalinity, but that much??

Thanks

 

[bertoni]

Halimeda, like coralline, deposits a lot of calcium carbonate, so it could consume a fair amount of calcium and alkalinity, just like a coral.