If you use Kalkwasser, do you use two-part as well?

[Andy V]

I recently moved into a new place, and I am having issues with low pH. It gets to 7.86 at night and goes to 8.06 during the day. When I open the windows for a day, it gets to 8.3, so obviously it's an issue with low ambient oxygen. Leaving windows open is not a solution, and even though I am on the 5th floor of my building (and highest nearby building), I am apprehensive about running the skimmer air-line outside.

So I was thinking of dripping kalkwasser, but I am not really sure about how to do it. Some things I have read say you are only supposed to mix a day's worth at a time. Other things say it's ok to mix up a weeks worth. I do not want to purchase a kalk stirrer. I was thinking of the Tunze system with the osmolator. Is this system of dripping kalk a good one?

Also, my understanding is that kalk only raises calcium but not alkalinity much. So how do you maintain alkalinity and calcium with kalk? I guess you wouldn't dose two-part?

 

[frank180reef]

I recently moved into a new place, and I am having issues with low pH. It gets to 7.86 at night and goes to 8.06 during the day. When I open the windows for a day, it gets to 8.3, so obviously it's an issue with low ambient oxygen. Leaving windows open is not a solution, and even though I am on the 5th floor of my building (and highest nearby building), I am apprehensive about running the skimmer air-line outside.

So I was thinking of dripping kalkwasser, but I am not really sure about how to do it. Some things I have read say you are only supposed to mix a day's worth at a time. Other things say it's ok to mix up a weeks worth. I do not want to purchase a kalk stirrer. I was thinking of the Tunze system with the osmolator. Is this system of dripping kalk a good one?

Also, my understanding is that kalk only raises calcium but not alkalinity much. So how do you maintain alkalinity and calcium with kalk? I guess you wouldn't dose two-part?

I wouldnt take this as gospel, but I drip around 200 ml an hour into my 300gallon system, I make up about 5 gallons at a time. I have a doser that drips in the 200ml an hour. It doesnt appear I need to dose much, but it is still a wip. My ph is supposidly 8.1 at 6 am . I calibrated my ph meter about a month ago

 

[afboundguy]

Kalk adds calcium and alk. The problem you might run into is if the tank's needs aren't met by the kalk. You can only saturate the kalk solution so much before it just doesn't mix in the water anymore. You can try to add vinegar or another carbon dose with the kalk to increase the amount the water can dissolve but it's not worth it IMO. I tried it and had a huge bacteria bloom

On my old 55 mixed reef all I did was use a kalk stirrer and ran the top off water through it and it more than kept up with the demand. I just had to keep on top of magnesium which I wasn't usually doing

Dripping kalk is a pain IMO. I initially did it when I had dino's out of necessity and it was hard to make sure the same amount went in daily due to the line clogging up. I'd say the best way is to use a stirrer or reactor and hook it up to your top off if you have one. Only small problem with that way is that the amount of kalk you put in in the tank is dependent on evaporation which changes with the seasons. That being said I never had a problem in any season with mine but I'm sure people have had problems.

Another option is to set up a kalk reservoir with a pump set up to run a few times a day to keep it stirred up. Then use a dosing pump so that you get the same amount every day.

As far as how much to mix up when dripping I would recommend only doing a day's worth at a time until you get the hang of it. You would crash your tank if you accidentally dripped a weeks worth of kalk into a tank and like I said it's kind of a pain dripping it because if you set up the drip in the morning for a constant drip rate I can almost guarantee it won't be the same rate when you get home later that night...

And there are plenty of people who dose 2 part and top off with kalk. Just kind of depends on the demand of your system. If you have something like my old 55 you can get away with just one. If my 55 was an SPS dominated system I'm sure I would have had to do both...

 

[JohnK]

Your PH is still staying within a safe range, I wouldn't be concerned.

If you do feel the need to start dripping kalk to up the PH, yes you can mix a lot of kalk at once and let it sit. There will be a little reaction with the Co2 in the air which will cause a crusty skin on the surface, but this is not a big deal.

If you do run a kalk drip through an ATO, keep in mind that if the tank loses any water you have the serious risk of a major PH spike that could do a lot of harm. If the ATO uses a pump that only produces an extremely slow flow (only a little more than the evaporation rate) you will have some insurance against a tank killing kalk overdose. Personally I use a cole-parmer peristaltic pump do drip my kalk (expensive but very good control of the dose).

Again though, can't say it enough, 7.86-8.06 is still within a safe range and I wouldn't do anything

 

[frank180reef]

I have tried the gravity kalk drip and agree it is very hard to do, due to the clogging that Dave mentions. I have had good luck with the doser (FWIW)

 

[Andy V]

Your PH is still staying within a safe range, I wouldn't be concerned.

If you do feel the need to start dripping kalk to up the PH, yes you can mix a lot of kalk at once and let it sit. There will be a little reaction with the Co2 in the air which will cause a crusty skin on the surface, but this is not a big deal.

If you do run a kalk drip through an ATO, keep in mind that if the tank loses any water you have the serious risk of a major PH spike that could do a lot of harm. If the ATO uses a pump that only produces an extremely slow flow (only a little more than the evaporation rate) you will have some insurance against a tank killing kalk overdose. Personally I use a cole-parmer peristaltic pump do drip my kalk (expensive but very good control of the dose).

Again though, can't say it enough, 7.86-8.06 is still within a safe range and I wouldn't do anything

Yeah, I really want to avoid doing this altogether. It just seems as if things in the tank aren't really doing that well despite all parameters being spot-on. I use controllers and peristaltic pumps with two-part now, so the parameters are very stable. For those paying attention, I have another post because I ramped up carbon dosing too fast and had some bacterial slime as a result. However the corals that don't look good haven't looked good for longer than I have been dosing.

It's just kind of bizarre because none of the SPS are doing well, and neither is a yellow-leather. Also a cyphastrea that I have had for years (and has been always very easy to keep, even through bad times) STN'd, but there are a few polyps that survived and look great. However the remaining corals all look good, except their colors aren't as vibrant as normal. I have ruled out pollutants, since I run purigen and did a 50% water change last week which did nothing. So my thought was that the pH was the issue, despite the fact that it's in an acceptable range.

BTW, I just calibrated the probe last week.

 

[frank180reef]

FWIW I would still temporarily stop the carbon dosing for a while and see if things improve

 

[inverted]

For the OP, pH is a function of alkalinity and CO2 (Not O2). Calcium Hydroxide (kalkwasser) reacts with the Co2 and produces calcium and bicarbonate (alkalinity) and raises the pH. It is basically a balanced additive, so it adds both calcium and alkalinity equally well. However, it has a very high pH, around 12.5, and can cause serious issues if added too fast. Best is to drip it slowly over the course of the day.

For me, it does not meet my calcium and alkalinity demands, so, I need to use vinegar and a small amount of two part as well. The vinegar is a carbon source though, so, it can cause issues. I only do so, because I want to dose a carbon source, but would not recommend doing so unless you understand carbon dosing, and really want to do so, and are not able to keep up with ca and alk, with kalk alone. Even dosing vinegar, it is often better to do so separately from kalk, because you have more control over dosing.

However, my doing is tightly controlled using a few alternative methods. I mix a 5 gallon bucket with kalk and vinegar. This is about 4-5 days worth. I use a Toms Aquatic Aqualift pump, but have a ball valve on the output side of the tube (from home depot for an RO/DI type line). I adjust the drip, with the ball valve, so that it is slightly faster than my evaporation. This way if the pump gets stuck on, it dosn't add too much and it will not add too much too quickly. However, the pH can still get too high, a pH over about 8.4 for more than a few minutes can cause precipitation of calcium carbonate and actually lower your ca and alk. So, I have my ATO controller plugged into a pH controller. If the pH goes above 8.25, the ATO is shut off until it drops back to 8.15. Also, the drip tends to slow down, so, I need to check on it every few days. The nice thing about the ball valve is opening and closing it a few times breaks the crud free, so, I rarely need to soak it in vinegar. However, occasionally this is necessary if too much build up occurs.


andyvalk, carbon dosing will cause the colors to get more pastel. If the colors are still bright, and there is a lot of pigment, it's probably a good thing. It is a sign of reduced inorganic nutrients, which should result in faster growth. If there is no pigment and the corals are looking white, they could be starving. One thing people don't realize with carbon dosing is not only can you feed more, you need to feed more. The corals will tend to grow faster, but can't obtain nutrients for tissue growth from zooxanthellae, so, they need food. Feeding more should help, as should adding amino acids. Aminos are popular because they are necessary for tissue growth, and add a nitrogen source, but do not add a phosphate source. Even if there is pigment and the corals are healthy aminos can help make the coral darker, by driving more zoox growth. The only thing is zoox growth tends to reduce coral skeletal growth, so, it's a balance between dark coloration and growth. Also, of course, too much N will result in browning.

 

[Andy V]

Yeah, what I meant was the CO2 levels in my house are high because it is fairly new construction. I am not going to use kalk...it just seems like a pain. I am also going to cut off the carbon dosing for now. What I am concerned about is that I don't want to have phosphate issues eventually, and I was hoping not to run GFO.

 

[inverted]

Your swing isn't that bad, but you could run the air line for you protein skimmer out of a window. For many, this is a better option than kalk.

As to carbon dosing, I definitely think it is an advanced method, and is not for everyone. I'm not sure why you don't want to run GFO though. It has a lot of benefits besides removing phosphate and really no risks as long as you do not add too much, too fast. Just add a bit and work up slowly. some corals, especially LPS can be shocked by sudden changes, but otherwise is quite safe.
Also can be more effective at removing phosphate than say Biopellets. Many brands of Biopellets are really for nitrate, not phosphate reduction. Other forms of carbon dosing and certain Biopellets ( depending on what they are made out of) may work well for phosphate too.

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[Andy V]

Your swing isn't that bad, but you could run the air line for you protein skimmer out of a window. For many, this is a better option than kalk.

As to carbon dosing, I definitely think it is an advanced method, and is not for everyone. I'm not sure why you don't want to run GFO though. It has a lot of benefits besides removing phosphate and really no risks as long as you do not add too much, too fast. Just add a bit and work up slowly. some corals, especially LPS can be shocked by sudden changes, but otherwise is quite safe.
Also can be more effective at removing phosphate than say Biopellets. Many brands of Biopellets are really for nitrate, not phosphate reduction. Other forms of carbon dosing and certain Biopellets ( depending on what they are made out of) may work well for phosphate too.

Sent from my iPhone using Tapatalk

I was using GFO on my last setup so I have quite a bit of experience with it and I liked it. My issue is that I have no more room in my sump for another pump to feed a media reactor, nor do I have any room under the tank for the reactor itself. So the reactor would have to go outside the stand and I would have to figure out how to feed it somehow.