Trying to Maintain a steady alk for my sps.

[salty_trout]

So the past few days I've been testing. In short, I tested the Alk initially, after three days, and after six days. It had averaged a drop of 0.166 dKh/day for both tests. I used the Hannah alk checker, along with my standard for assurance. Basically, my (130ish gallon) system went from 8.2 to 7.0 dKh from the 23rd at 2pm to the 29th at now. The big question being what should I do? How much should I add daily? I usually use the brs reef calculator, but wanted some input. I like my alkalinity around 7.8-8, only because I thought this to be a better alk for sps. That being said, I've seen a ton of tanks booming with sticks and a sky high alk. Also, when should I add and how slow? Is it enough consumption to hook a dosing pump up yet?

 

[Pete_the_Puma]

I think it is definitely time to start replenishing alkalinity, and by extension calcium and magnesium.

The questions is: What is your planned strategy to replenish those? Broadly there are 2 ways to do this:

Dosing
or
Calcium reactors

Most people who dose do so with a dosing pumps although there a successful reefers out there who prefer to dose "by hand" . There are a TON of different versions of supplements and "how much" you dose depends on which one you choose. These are ESV Bi-ionic, BRS basic 2 part, Red Sea "Reef foundation" and Triton "Core" to name a few. These all replenish Alkalinity, calcium and magnesium with some also adding "trace elements".

The quantity you will need for each depends on which product you choose but they all have specific instructions on how much to add. If I could make one recommendation is to raise your alk SLOWLY back to 8ish where you want it, many a tank have crashed due to rapid increases in alkalinity... Basically I would recommend starting with 50% of whatever dosage is recommended for the product you choose and checking your Alk daily, increasing the dose a little bit every day until Alk is slowly increasing, then cutting back when you reach your target.

Most people dose alkalinity at night, it slightly increases the pH which tends to be lower at night so the dosing helps keeps things more steady. Usually they recommend dosing into a high flow area of the sump, and dosing the components minutes if not hours apart so that the calcium and Alkalinity do not precipitate on the spot.

Calcium reactors tend to be a little more complicated up front with easier dosing once they are set up. I'd probably recommend dosing for now.

 

[Crashjack]

The third option is kalkwasser. Kalkwasser (kalk) is typically the cheapest solution and also helps pH. There are drawbacks, but all of the solutions have drawbacks. Kalk also has the benefit of automatically adding balanced alk/Ca, and it can be integrated into your ATO, eliminating the need for additional dosing pumps, CO2 bottles, and so forth. IMO, the biggest problems with kalk are: 1) When you have integrated into your ATO and your tank is young and uptake is low, you might have to switch back and forth between running kalk and running straight RO. Some people just run kalk at night, which also keeps pH from dropping so much at night. I use a 3-way valve with my kalk stirrer to where one position runs straight RO and the other position runs through the stirrer, which allows me to quickly and easily switch from one to the other. 2) It is very possible that eventually, your tank's demand for alk/Ca will be greater than what you can add back with kalk even if you run all of your top-off as kalk. The good news is, if this happens you might be able to adjust with manual dosing every few days, once every week or every two weeks or whatever. You can also opt for one of the other two methods (probably dosing) but dose a lot less than you would if you weren't running kalk.

 

[salty_trout]

thanks crashjack, however I don't consider kalkwasser a method to control alk since all kalk really does is replace daily lost calcium and increase pH. That being said, I've been using brs kalk in my ATO for about 5 months now. Keeps my pH bw 8.2-8.45, based on the apex. Fortunately for me, HW wiegandt reefer puts plenty of Magnesium in their mix because its typically 1300-1400ppm every time I test, so I never even have to add any with my biweekly water changes, would water change once a week, but I am chasing nutrients as always. More fish coming after qt tho. I added liquid calcium like 3 times since I started the tank, every time I test its 440-450 ppm using a red sea pro test kit, kalk keeps it steady. I guess the big question is how much should you let your alk drift before adding more 2 part, in this case sodium bicarb.

 

[Crashjack]

Kalk maintains alk just like it does Ca. However because it is balanced, it can't effectively raise one or the other (it would raise both). There are situations where alk and Ca can become unbalanced when only using kalk, but it would be something like unbalanced alk/Ca in your salt so your water changes create the imbalance, your Mg is too low, or you have a lot of precipitation. I recommend doing some searches in this forum (Randy's forum) as he has written volumes on the subject and is the resident expert. Some of it gets pretty technical, but he always includes information that everybody (like me) can understand.

 

[Crustaceon]

I’m dripping supersaturated kalk (mixed with a little vinegar) into my 20g and it’s keeping dkh at 7.5. IME the key to using kalk only is boosting tank evaporation to offset how much kalk solution you’ll need to add per day. I did this by simply by adding a fan to blow on the waters’ surface. Anything within 7-12 dkh is fine provided it’s a stable number and you feed the tank accordingly. As a side benefit, the addition of vinegar is acting as a carbon source for bacteria which my tunze nano skimmer is removing along with excess nitrates and phosphates. I just have to make sure the tank is well fed, which isn’t a problem considering its only fishie residents are a pair of clowns that i’m hoping will become plump and spawn soon.

 

[hart24601]

I would say since kalk does raise calcium and alk if you want to know the true tank demand you should top using kalk but if you just want to know how much 2 part to add you can keep using it. I would start with BRS 2 part and manually dose it daily and see how the system reacts, however I would wait until the alk naturally drops to 8 or so and try to keep it around that range.

 

[cain720]

+1 for kalkwasser

The biggest downside is finding the perfect solution strength to hold your alk and Ca steady. For me, it's less than an exact science, and I usually just test alkalinity before I refill my top-off and make small adjustments to my kalk dose depending on if my alk rose or fell since my last test.

 

[salty_trout]

Kalk maintains alk just like it does Ca. However because it is balanced, it can't effectively raise one or the other (it would raise both). There are situations where alk and Ca can become unbalanced when only using kalk, but it would be something like unbalanced alk/Ca in your salt so your water changes create the imbalance, your Mg is too low, or you have a lot of precipitation. I recommend doing some searches in this forum (Randy's forum) as he has written volumes on the subject and is the resident expert. Some of it gets pretty technical, but he always includes information that everybody (like me) can understand.

I am a chemist with published research in organometalics, it's not the chemistry I don't understand. I just wanted some feedback on how much sodium bicarbonate to dose or rather the best time of day to dose it. Here is a question for you though, if kalk does maintain alk like you are saying how is that my reef consumes alkalinity while being dosed continually with kalkwasser from the ato? I always thought one of the beauties of using kalk was it didn't effect your alkalinity it just provided daily lost calcium and raises pH, which would make sense since its only being added in small amounts from evaporation and, although a kalk solution itself does have a high dkh its effect, from my understanding, should be negligible on the systems alkalinity.... sodium bicarbonate VS Calcium hydroxide it would seem to be pretty obvious which one effects dkh more since "1 dKH is defined as 17.86 milligrams (mg) of calcium carbonate per litre of water" . However, this is just my understanding. My magnesium is always on point also, I might add. The effluent from my ATO is 20dkH I evaporate about 2ish gallons a day. I imagine I'm just going to hook the dos up to the Neptune and start at 5-10ml of sodium bicarb a day and see where that keeps me. With that being said I'm open to reading any literature you or anyone else recommends on the subject.

 

[Crustaceon]

Most systems will outstrip the buffering capability of normally saturated Kalkwasser in ato unless you artificially increase the evaporation rate of your system, thusly increasing the allowed dosage of saturated kalkwasser solution and as a result, adding more alkalinity. A common method is using a fan to blow air across the water surface of the display or sump. The problem here is dealing with the ph boosting nature of calcium hydroxide and the fact that calcium hydroxide is water insoluble, which limits a normal mixture to 2 tsp per gallon of rodi. Put enough into your system to keep up with a typical alkalinity demand and ph can easily jump to 8.8. By adding vinegar to the kalkwasser, much more can be dissolved into a gallon of rodi, making the solution more potent while simultaneously reducing the impact dosing an increased amount has on ph (typically by .20-25). As an added benefit/side affect, using vinegar with kalkwasser will act as a method of carbon dosing, which will dramatically decrease nitrates and phosphates if you have a protein skimmer in your system. This could mean eliminating hair algae from a display at first but having to feed your tank like crazy to keep nutrients in the system or having phosphates become depleted and then having nitrates skyrocket because the beneficial bacteria grown from the carbon source needs Po4 to effectively reduce No3.

So in a nutshell, Kalkwasser can work fine but lacks the adjustability and precision of 2-part dosing and require more setup to keep up with higher alkalinity demand. It’s more about mixing and adding kalk a certain way and not deviating from that method, instead allowing the tank to settle at a certain dkh/cal within accepted ranges. On the plus side, kalkwasser is dirt cheap. You mentioned sodium bicarbonate and that will absolutely keep up with your tank’s demand but will require a doser, keeping records of tank usage and adjusting the dose accordingly. Lastly, don’t be surprised if you use three times as much alkalinity solution as calcium or magnesium solution. It’s normal for some tanks to lose as much as 1 dkh per day when they’re full of coral and coralline algae. I think in the vast majority of situations, if you’re losing alkalinity, it’s a great time to start dosing soda carbonate/bicarbonate. Start with a small amount, maybe 30ml per day, spread out the dosage into 4 or 8 events and set your calcium/magnesium doses 30 minutes apart to minimize stress on your critters. Test every three days and add or subtract 1 ml from one dosing time. Need more or less? Take or add 1 ml from another dosing time etc.

 

[Crashjack]

I am a chemist with published research in organometalics

Well, you've got me beat. Read these, and there are plenty more in the sticky at the top.

[URL]http://reefkeeping.com/issues/2005-01/rhf/index.htm
http://reefkeeping.com/issues/2004-12/rhf/index.htm
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm[/URL]

 

[salty_trout]

Well, you've got me beat. Read these, and there are plenty more in the sticky at the top.

http://reefkeeping.com/issues/2005-01/rhf/index.htm
http://reefkeeping.com/issues/2004-12/rhf/index.htm
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm

I highly doubt that lol i'm a major burnout, the paper only made it to Organic Letters. haha. I will check all of these, thanks.

Most systems will outstrip the buffering capability of normally saturated Kalkwasser in ato unless you artificially increase the evaporation rate of your system, thusly increasing the allowed dosage of saturated kalkwasser solution and as a result, adding more alkalinity. A common method is using a fan to blow air across the water surface of the display or sump. The problem here is dealing with the ph boosting nature of calcium hydroxide and the fact that calcium hydroxide is water insoluble, which limits a normal mixture to 2 tsp per gallon of rodi. Put enough into your system to keep up with a typical alkalinity demand and ph can easily jump to 8.8. By adding vinegar to the kalkwasser, much more can be dissolved into a gallon of rodi, making the solution more potent while simultaneously reducing the impact dosing an increased amount has on ph (typically by .20-25). As an added benefit/side affect, using vinegar with kalkwasser will act as a method of carbon dosing, which will dramatically decrease nitrates and phosphates if you have a protein skimmer in your system. This could mean eliminating hair algae from a display at first but having to feed your tank like crazy to keep nutrients in the system or having phosphates become depleted and then having nitrates skyrocket because the beneficial bacteria grown from the carbon source needs Po4 to effectively reduce No3.

So in a nutshell, Kalkwasser can work fine but lacks the adjustability and precision of 2-part dosing and require more setup to keep up with higher alkalinity demand. It’s more about mixing and adding kalk a certain way and not deviating from that method, instead allowing the tank to settle at a certain dkh/cal within accepted ranges. On the plus side, kalkwasser is dirt cheap. You mentioned sodium bicarbonate and that will absolutely keep up with your tank’s demand but will require a doser, keeping records of tank usage and adjusting the dose accordingly. Lastly, don’t be surprised if you use three times as much alkalinity solution as calcium or magnesium solution. It’s normal for some tanks to lose as much as 1 dkh per day when they’re full of coral and coralline algae. I think in the vast majority of situations, if you’re losing alkalinity, it’s a great time to start dosing soda carbonate/bicarbonate. Start with a small amount, maybe 30ml per day, spread out the dosage into 4 or 8 events and set your calcium/magnesium doses 30 minutes apart to minimize stress on your critters. Test every three days and add or subtract 1 ml from one dosing time. Need more or less? Take or add 1 ml from another dosing time etc.

Makes sense. When my demand is higher Ill try really adding the kalk to it perhaps and seeing If I can add less bicarb (if that is what you guys are saying). Right now its in a 30 gallon ATO reservoir with 2tsp per gallon my tunze ATO is sitting on a small riser so it doesn't touch the sediment at the b0ttom.

 

[SeaDweller]

http://reef.diesyst.com/chemcalc/chemcalc.html

 

[Crustaceon]

I actually run kalkwasser as a supplement to 2-part dosing on my 120g system. I does help a little bit to reduce the amount of sodium carbonate/bicarbonate. But I mainly use it for magnesium dosing as I use Brightwell’s Kalk +2 and that alone seems to handle about 90% of my system’s magnesium demand.