High Calcium and Low Alk

[obring]

Okay... keep in mind that I am not a chemist, and that the hardest part of getting into the hobby has been understanding all the chemistry side of it. For roughly ten months I have measured alkalinity and thought it to be acceptable, at 7.7 - 9.0 dKH range. Just today I found out that is not the case. It started with what i thought was a bloom of brown algue on my substrate (I erronously atrributed it to phosphate... but after buying about 4 pounds of caulerpa and two weeks later...phosphate is neglegible). That lead me to do daily testing again, to discover slightly elevated nitrate levels, which could be due to a slight overcrowding and not using a skimmer... Now... my true question is.... what is the acceptable range for alk?? my LFS told me that it should be around 11.2 dKH... but i thought that 9.0 was high. I also have extemely high calcium (600 ppm) and i can't figure out what is goign on. The tank looks great and so does the fish. I have a rock with about 21 blkue mushrooms and they are thriving and really nice and big. I attempted to raise the alk by adding "alkalinity plus" (part one) from NatuReef... i dosed 5 ml in the morning and 5 ml about an hour ago and just measured my alk at 6.3 dKH. Will be doing a water change tomorrow... any thoughts and advice is always appreciated!

[bongobrian]

Hey don't kick yourself for not knowing all of the chemistry involved with reefing! there is so much of it to know, I'm not sure if any of us will ever know it all ;) I'm no expert either, but I do know that very high calcium levels such as yours will drive the alkalinity levels down. I don't measure my levels in dkh so I'm not sure on the translation but I know good alkalinity levels fall between 3.2-3.6 meq/l. Generally the higher it is in that range the better. Again I'm not sure of the target level of Alkalinity on the dkh scale, but I think if you can get your levels up above 7 dkh, you should start seeing a drop in calcium. Maybe someone out there can give us a scale converstion between meq/l and dkh.

[eses]

1 meq/l = 2.8KH, GH, dH.

So by that scale your Alk comes out to 2.5 meq/l. Which is technically okay, but 3.2-3.6 meq/l is more optimal for promoting corraline growth.

With your calcium so high I think you also need to be careful about raising your Alk too quickly or it will percipitate the calcium from the water, and you'll get calcium fallout in the tank. I could be wrong in that regard though, but either way you will want to raise you Alk slowly.

[alf3482]

Alk target i suggest between 8.0 and 12.5.IMO so you are not that far off an alk alittle but not much. Your Ca is high at 600 but with your alk level low this is to be expected. One has a see-saw effect on the other low alk= higher ca , low ca = higher alk. so the trick is to move your alk no more than 1.0dkh at a time as your alk rises the ca will fall, but as stated before if you move it to quick than you could cause a snow storm and the ca will fall to far. continue to raise alk with what ever product you want, till you reach desired levels. I solved this problem a year ago with the help of this board. Do you drip kalk? if you do not putting it in may be helpful for you, this a long with raising my Salinity up to 1.025 fixed my problem. I was chasing the #'s for months put kalk on line and raised my salinity from 1.023 to 1.025 solved my problem in a matter of weeks. and if one falls i adust accordingly with buffer, but only when needed. but it is very rare that it needs it.HTH

[obring]

Thanks for all the input. I have been dripping kalk for top-off since the begining... and keept salinity between 1.023 and 1.025, on the lower spectrum of that range though... will let it move to the higher side and see what happens. I have been using distilled water for changes and top=off, but this new LFS can give me the RO water...so I will be doing that from now on. I have been using the Alkalinity Plus from NatuReef...and have not thought about the see-saw effect! I am glad I checked here before adding anymore. According to the table i have a 3.2 mequ/l is a 9.1 dKH. This morning i measured alk again and it is at 2.5 mequ/l... so i am guessing i am mopving in the right direction.
I am also checking out "Restore" two part supplement... has anyone heard of it? The LFS told me that it is much better than NatuReef and no supplements are needed. Any feedback on that?

[alf3482]

I do not use store bought additives so i can not comment on that product. I use a home made buffer for raising alk. But i have been told that the two part suplements are good. but no experince my self. good luck

[Toadally]

I recently struggled with this very problem, but I had low calcium. I changed 1/3 of my water and then used a two part additive system to get things back in shape. Now my levels are at 400ppm cal. / 11.6dkh. Just do a major water change to get things back in shape. I recommend using a two part additive like Kent Tech CB or C Balance. HTH

[obring]

THIS HAS BEEN SO INTERESTING! I feel like such a chemist! LOL.

Tonight my alk is still 2.5 mequ/l but the Ca went down to 550... tomorrow I will do a ten gall water change... and then the same four days later... will keep everyone posted on this... I was actually getting bored...not anymore!

[eses]

Just for the record and to add my experience, I have had no luck at all using the Kent Tech AB two part buffering system. Even using quadruple the dose I see no effects with it. I am more of a believer in just using kalk and something like kent superbuffer dk/h to raise your alk.

[Toadally]

eses - I wasn't seeing too much of an effect either at first. I then started using the maximum dose that they suggest which was 30ml. of each part every twelve hours. It took over a week before the calcium strated to climb. I kept testing every few days and when it got to the values I wanted I just backed off to maintain. It's very easy to maintain the levels I have now. Just my experience.....

[Randy Holmes-Farley]

obring:

As calcium and carbonate precipitate to form calcium carebonate, the calcium level drops much more slowly (on a percentage basis) than the alkalinity level. Thus it takes a while for the Ca++ level to drop.

IMO, there is no reason to worry about alkalinity of 2.5 meq/L (7 dKH) That's seawater level, and many people keep tanks there. Unless you have a problem, I would not agonize over the alkalinity.

I agree that the calcium is a bit high, and can be allowed to drop to about 400 ppm.


< Just today I found out that is not the case. It started with what i thought was a bloom of brown algue on my substrate (I erronously atrributed it to phosphate... but after buying about 4 pounds of caulerpa and two weeks later...phosphate is neglegible). >

I'm not sure how you conclude phosphate isn't the problem. In an active algae growth situation, phosphate is often low as the algae consume it as fast as it is produced by feeding. The importnat thing, however, is that there is a large flux of phosphate from food into algae. Unless the caulerpa is extensive enough to use it all up, the other algae forms may still be getting plenty.

Nitrate alone is not sufficient to cause an algae "problem". Many people have tanks with 10-50 ppm nitrate without algae problems.

[obring]

Randy: Thanks a lot for your input. It is trully reassuring to know that you all are so diligent in helping others. I have posted in other boards and that is not the case.

To answer how I concluded no prob with phospate...for the last seven days it has measured to zero... which is why i said that is not the problem.

I also thought about something else... they way I built up the LR in the tank (I have added to what is shown in the web page) I ended up corraling about 1/4 of the tank into an area that i can not syphon when vaccuming the sub... could that lead to problems? I was very carefull when i did the initial lay-out of the LR...but I guess I kinda forget after that. You mentioned the precipitation of calcium, and I am sure it has a lot of THAT back in that corner....

As always...really apreciate all your inputs...

[Randy Holmes-Farley]

obring:

Many people find that when they have an algae problem, the phosphate levels are low BECAUSE there is so much algae consuming it. In a sense, the undesirable algae is acting as a nutrient removal system. BUT, there is still an input of phosphate from some source that is fueling the outbreak.

If this is the case, then you can do either of two things:

1. Stop the phosphate additions.
or
2. Provide another, better sink for the phosphate.

In the first category are such things as using RO/DI water, cutting back on food, and better skimming.

In the second category are such things as using macroalgae as a scrubber, using limewater, and using phosphate removal products like Phosguard.