Time to raise alkalinity?

slfcaptain

Active Member
My last thread about alkalinity got nuked in the crash and I need some more help.

The alkalinity in my tank has been on the low side, 7 ish, for the past few months and water changes are barely keeping up with it. The last several alk tests are:
9/12: 7.3 dKH, Ca 415ppm, Mg 1340ppm, pH 8.0
9/13: 7.1 dKH
9/14: 6.85 dKH, Ca 410ppm, pH 8.0
9/15: added GFO and purigen to the tank to help control an algae problem
9/16: 6.4 dKH

There is clearly a downward trend in the alk. Is this the time to add something (like baking soda) to bring the alk up?
 

PSU4ME

JoePa lives on!!!
Staff member
PREMIUM
Yes..... Gfo will drop alk as well. Try getting a 2 part solution.
 

saltfan

Well-Known Member
+1^ I use B-ionic but but will be switching to a 2 part powder from BRS as soon as I can spend the little bit exta to get the dosing pump combo...
 

DaveK

Well-Known Member
Generally you use kalkwasser to help maintain calcium. Two part is also used for this and to maintain alkalinity.

One word of caution. If you add any additive be careful. If you don't see some improvement with modest amounts, do not go overboard and add massive amounts. That's a real good way to mess up your reef and destabilize everything. In some cases your better off leaving things along, and doing water changes, even though parameters are not quite right. As you have seen, making a change in one place can make a change some place else too.

It also helps to test your new water and see where that is. For example if your dKH is at 6 with your new water, it's not going to go above that in your tank with out using additives.
 

PSU4ME

JoePa lives on!!!
Staff member
PREMIUM
Good advice from Dave.... You need to have a complete plan. Make sure you are able to measure improvement before you go adding a bunch. Figure out your gallons and plan to add enough alk supplement to raise it .5 dkh..... That is clearly measurable and won't swing your tank drastically. Once you get your ratios in range (note in range, don't shoot for a specific number), you need to make sure your water changes support that. From there you can measure your depletion rate and dose (equally ca/alk) to maintain that level. Kalkwasser will help, helps a bunch on ph stability as well. I really like kalk +2 by bright well.
 

slfcaptain

Active Member
Fresh saltwater is at 10 dKH so I was hoping weekly 25% water changes would bring it up but it hasnt and the GFO seems to have caused a quick drop.

I was thinking about getting the BRS kalkwasser starter kit. It has additives to raise Alk, Ca, and Mg separately plus the kalkwasser. I was going to get Alk in range then if I continue to see a drop in Alk I would add the kalk to my ATO.


Steve
 

Bearjohnson

Well-Known Member
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RS Ambassador
IMO if you're going to dose to raise your alk levels by using a two part or just a plain alk additive, then why add another solution like kalkwasser into the equation?

I only mention this because I was at the same crossroad a few months ago and after some research and the thought of keeping things simple, I figured it would be best to dose as needed to maintain levels.

By using a two part solution you'll dial in the numbers fairly quickly and maintain a better handle on your tank parameters with ease without major swings. It seems to me with a tank that size, once you dial it in, your parameter requirements should be maintained relatively easy.

I'm sure you're familiar with Kalkwasser and it's certainly an option however, you do need to approach it carefully.

Just my $0.02 worth:)
 

slfcaptain

Active Member
IMO if you're going to dose to raise your alk levels by using a two part or just a plain alk additive, then why add another solution like kalkwasser into the equation? 

Its my understanding that kalkwasser is not used to raise levels just to maintain. So I would need to dose to get in range then (if needed) use kalkwasser in the ATO to maintain. I should have pretty low demand (not a lot of corals) and kalkwasser should keep up (I evaporate about 0.25-0.5g/day). Of coarse I would do all the necessary testing to estimate Alk, Ca, Mg uptake.

Steve
 

slfcaptain

Active Member
I haven't added any additives yet and have been keeping an eye on my Alk. Monday I did a 25% water change and the Alk readings during the week are:
Tuesday: Alk 7.0 dKH, Ca 425ppm, Mg 1240ppm
Wednesday: Alk 6.85 dKH
Friday: Alk 6.55 dKH, Ca 405ppm, Mg 1320ppm (Tuesday's Mg reading is an outlier, all other Mg tests were in the 1300's)

Looks like the tank is dropping about 0.15 dKH per day. I ended up buying the BRS 2-part kit and the Hanna Checker Alk tester but it won't arrive until Monday. Am I ok waiting until then to do something or should I use baking soda now to bring up the Alk?
 

NJ Reefer

Active Member
PREMIUM
Steve, I know this is an old thread, but I am wondering what you wound up doing. Did you dose 2 part, or go with the Kalkwasser? I am having a somewhat faster drop in Alk (9 ppm per day or 0.5 dKH). I am adding baking soda daily to bring the Alk back to a reasonable level. But I need to figure out how to deal with this long term.
 

slfcaptain

Active Member
I am using the BRS bulk 2-part. I tried using kalk for a little while and it did a great job of maintaining levels but it may have caused my skimmer to go nuts. I say 'may have' because the skimmer was breaking in at the time so i dont know for sure why it produced so much skimmate. I found some anecdotal accounts of kalk causing skimmers to skim more.

The BRS 2 part is pretty cheap and easy to dose. You just have to come up with a daily dosing scheme to maintain the levels you want.

steve
 

slfcaptain

Active Member
BTW, make sure you Mg is in range. If its out it can cause stuff to precipitate out throwing your alk and Ca out of whack.

steve
 

NJ Reefer

Active Member
PREMIUM
Thanks Steve. My plan is to simplify this as much as possible, and the Kalk seems to be the simplest. Did you find it maintained the Alk sufficiently? If I do the 2-part dosing, do you use the BRS dosing pumps, or are you dosing daily by hand?


Sent from my iPhone using Tapatalk
 

Bearjohnson

Well-Known Member
PREMIUM
RS Ambassador
Manual dosing at first seems like a great idea but it will get old real fast. I'd consider a 3 head dosing pump and I also think if you start dosing alk, mag, & calcium, your need for Kalkwasser will more than likely be a waste of money.
 

slfcaptain

Active Member
I dose manually. Buying pumps is not in the budget at the time.

I think you'll be able to use kalk to keep up with 0.5 dKH per day. When I tried it I started with either 0.5 tsp or 1 tsp of kalk per gallon and stuck with that for a few days. I tested and then I adjusted the dose until I could maintain stable parameters. As long as your evaporation rate is sufficient you'll do fine with kalk. It would be a good idea to get some 2 part when you buy the kalk. You'll want use the 2 part to get everything in range and then the kalk to maintain.

steve
 

reefer gladness

Well-Known Member
You really want to be testing for magnesium if dosing kalk. Kalkwasser is an easy and cheap way to maintain calcium and alk but it does deplete magnesium from the system quickly.

Another RS member posted about using Brightwell Aquatics kalk with magnesium and strontium mixed in. Haven't tried that brand yet but it's next on my list. I go through so much magnesium that I get it by the gallon now.
 

NJ Reefer

Active Member
PREMIUM
Thanks guys. I believe I will try the Kalkwasser from BRS, once I get my other levels up. I have my Alk at 159 ppm now using baking soda (drops about 9 ppm daily). My calcium is 420, but magnesium is only 1120. Do you have suggestions from raising the magnesium levels? I see magnesium chloride and magnesium sulfate at BRS. They recommend combining both of them.
 
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