Going from Kalk to 2 part...questions

[Ferrell]

Question: sodium carbonate (soda ash) or sodium bicarbonate for two part dosing? Read somewhere where bicarbonate will lower ph. Will soda ash do the same? What do y’all use? Where should it start?

Using about 1 gallon of full strength kalk in ato due to evaporation and dose 75 ml nightly to keep at 8.3. Don’t want the start too fast. Want to dose Alk on the hour and Ca on the half hour. Have program generator for apex OSC program. Any suggestions would be great. Liked the kalk because it kept ph above 8.0. Now floating in the 7.8-7.9 range prob because using sodium bicarbonate.

Background :
75/30, socks, skimmer, ato running kalk at full strength
Alk. Try to keep at 8.3 and that’s the problem
440 Ca
1500 Mg
5 Nitrate
0 phosphate
No fish right now, laying fallow because lost all fish to velvet a few weeks back. (5 fish)
28-30 growing frags of lps, 3 sps (stylos pocillipora, monti), couple mushrooms.
Normal shelled CUC, nassarius, cerith, Tonga, turbo

Was doing fine with normal weather with heat on, couple of gallons of evap daily kept the Alk up to 8.2-8.3. Now in spring and no air/heat only getting about a gallon of evaporation and Alk is continually low. I test when I get home from work, 4-5 am, each night with Red Sea or Hanna and it’s consistently 7.5-7.6. I dose 75 ml of sodium bicarbonate solution according to BRS calculator and bring back up to 8.3. Decided to start dosing with BRS doser to keep it more stable. Starting out with 50 ml and going to keep increasing until at 8.2-8.3.
I’m just chugging along trying to achieve some sort of balance.
Regards to all
F

 

[Crabs McJones]

Sodium Bicarbonate has a lowering effect on PH, Sodium Carbonate (soda ash) has a temporary raising effect on PH I believe.

 

[chipmunkofdoom2]

The pH-lowering effect when dosing sodium bicarbonate (baking soda) is very small and only temporary. Over time, the pH will return to normal. Likewise, any pH increase you get from sodium carbonate (soda ash) is also temporary, and your pH will return to baseline after the CO2 reaches equilibrium between the surrounding air and your tank.

Per Randy's DIY two-part guide, sodium carbonate (soda ash) will raise your pH by about 0.3 units for every 1.4 dKh that you dose. Sodium bicarbonate (baking soda) will lower your pH by only o.o4 units for every 1.4 dKh that you dose.

 

[gurumasta]

I would dose the same amount of limewater every day. Whatever your minimum annual top-off is how much limewater you should dose. So if in the summer you have the least evaporation and that is a gallon then you should dose a gallon of limewater year round. Then have the ATO on its own system for the seasons where you evaporate more. I personally dose a gallon of limewater a day spread out every six hours 1/4 gallon year round. My top off reservoir varies depending on the season.

Then you your pH / Alk / Ca will be primarily driven by the limewater and you can supplement the two part. Once you figure out how much two part you need daily its set it and forget it. Just test your alk a few times a week to make sure the dosing is being done accurately. This will save you money and will be more stable.

 

[Ferrell]

I would dose the same amount of limewater every day. Whatever your minimum annual top-off is how much limewater you should dose. So if in the summer you have the least evaporation and that is a gallon then you should dose a gallon of limewater year round. Then have the ATO on its own system for the seasons where you evaporate more. I personally dose a gallon of limewater a day spread out every six hours 1/4 gallon year round. My top off reservoir varies depending on the season.

Then you your pH / Alk / Ca will be primarily driven by the limewater and you can supplement the two part. Once you figure out how much two part you need daily its set it and forget it. Just test your alk a few times a week to make sure the dosing is being done accurately. This will save you money and will be more stable.

Interesting. I like the kalk but couldn’t figure a way to do it and the 2 part. How do you dose it? Timed pump? Doser? Homemade dripper? Hand dosing?
Very interesting idea

 

[rkpetersen]

Interesting. I like the kalk but couldn’t figure a way to do it and the 2 part. How do you dose it? Timed pump? Doser? Homemade dripper? Hand dosing?
Very interesting idea

My setup is similar but a bit different. I have the ATO running on an oscillating cycle that replenishes a set amount of water into the system each day. This water first passes through a kalk reactor. I have sensors set up to tell me if the water level drops or raises beyond certain limits. My evaporative loss is remarkably consistent from day to day, but if the level starts to drop slightly I just make up the difference with manual addition of more RODI water. I also dose 2-part with a Neptune DOS. And I use CO2 scrubbing at night to keep the pH from falling too far. This trifecta of techniques is finally keeping my alk and pH where I want them.

 

[Greybeard]

I like Kalk... but as you've figured out, it can't keep up with demand on many of our systems. Just because you need 2pt (or some way of dosing Calk/Alk) doesn't mean you have to stop with the Kalkwasser! The Kalk will help keep the pH up, even with the added Calc/Alk dosing.

I'm with the gentleman above... a set dose of Kalk, something less than your minimum daily evaporation, and dose 2pt (ESV B-Ionic, in my case) based on consumption calculated with that kalk dosage.

For instance, I'm dosing 1/4 gallon (950ml) of Kalk a day. Cheap dosing pump on my Apex. Refill 2 gallon container, once a week, no big deal.

With that dosage running, day after a water change, I measured Calc and Alk. Did nothing, continue Kalkwasser dose. 2 days later, I re-measured Calc and Alk. Divide by two, you've got daily consumption of each. From there, it's not hard to calculate daily dose. Most (all?) 2pt vendors have a formula or calculator.

 

[gurumasta]

Interesting. I like the kalk but couldn’t figure a way to do it and the 2 part. How do you dose it? Timed pump? Doser? Homemade dripper? Hand dosing?
Very interesting idea

I have a 4 head dosing pump that doses the lime water and the 2 part. Lime water is dosed 4 times a day and the 2 part is dosed twice each. Once in the AM and once in the PM. Limewater is every 6 hours. I have the times set so nothing doses within an hour of each other. I use 30 gallon barrels to store the limewater and the top off.

The ATO is just setup on a float switch and does it’s own thing as it is just RO water.

Pretty simple and consistent. Once and a while I have to increase my 2 part dosing based off of demand. Eventually I will prob have to swap the 2 part with a Ca reactor. I have tons of sps corals and this setup has worked well for me.

Hope that helps!

 

[Ferrell]

Thanks for the info. Fairly new to the reef keeping portion of the hobby and dosing especially. Thought the kalk in the ato would last a little longer but that’s a good thing. I’ll look into adding the kalk as well. Good info and happy reefing.

 

[DesertReefT4r]

Wait are you add just 1 gallon of saturated kalk to a larger ATO res? If so you can just add more kalk to the ATO directly. I had no issues keeping ca, alk and ph up with kalk in a 5g ATO res and was not near full saturation. Tank was 75g mostly sps, had a fairly high demand for ca and alk. The thing I dont like about 2 part is it increases salinity over time, kalk does not do this. Also the need for dosers or manual dosing for 2 part. Kalk imo is way cheaper and easier.

 

[Ferrell]

Wait are you add just 1 gallon of saturated kalk to a larger ATO res? If so you can just add more kalk to the ATO directly. I had no issues keeping ca, alk and ph up with kalk in a 5g ATO res and was not near full saturation. Tank was 75g mostly sps, had a fairly high demand for ca and alk.

No, my tank only evaporates 1 gallon per day right now where it was evaporating 2 gallons per day in the winter when we had the heat on. My ato reservoir holds 2.5 gallons to which I added 5 teaspoons of kalk. Dosing one gallon of saturated kalk would not keep Alk up. Each day it would evap 1 gallon which the ato would replenish with saturated kalk. The Alk would go from 8.3 down to 7.6 each day so I would have to supplement Alk daily. I wanted something to prevent the constant swings so going to two part and dose more often.
I may build a dripper or dose the kalk another way as it has clogged my ato and has been very caustic to my pump(s). Another doser may be the answer as I like the benefits of the kalk. Didn’t realize until today that people are using both.