A problem of kh...

[tinycrazycrawler]

I own a full Berlinese 300 lt. tank.
Is 3 month old, and is going well.
I have a kalkwasser reactor, filled with 3 spoons every week of CaOh. All values were OK, also if only in this days I've a fully understand and operative reactor ( Ca was OK before, because I've mainly little acro frags).
I've read of the advantages of deep sand bed and I added 15 days ago 5 cm of aragonite sugar sized sand.
From that day the kh dropped from 9 to 5 KH (2 meq), and, more important, adding the Kh buffer from Kent and another brand (Elos) the KH go up only to 6, and for only one day! After, goes back to 5. Think that I've added nearly all a medium bottle of kh buffer in one week.
Now my values are
Ph 8 morning, 8,4 evening.
Kh 5-6
Ca 400
Mg 1150
Now, I've read that a new aragonite sand bed can bond a lot of kh hardness, but I become worried. When it will end to make this? Is possibile that 'll never end , or that my sand bed will become petrified?
The only problem for now that I am able to solve alone is to add more Mg.
Someone can help??
Many many thanks, and excuse my bad english,
Marco

 

[randy holmes-farley]

Fresh aragonite can take down the alkalinity (and also calcium, but that usually goes unnoticed). Usually, the process ends fairly rapidly (a day or less, IME) as magnesium, phosphate, and organics cover the surface of the aragonite.

If it doesn't get back to normal soon, try testing the magnesium level to see if it is close to normal.

Beyond that, maybe you have simply increased the growth rate of the frags. The aragonite may have reduced the phosphate in solution, at least temporarily, and they may be growing faster now.

 

[tinycrazycrawler]

Is possibile that 15 acroporas (growing well) *from 1 to 4 inches long* can reduce the KH so, that a full bottle 16 oz Kent kh+ used in 10 days isn't able to raise it?
Thanks,
Marco

 

[randy holmes-farley]

Well, let's see:

I cannot tell from Kent's web site how much could be in that bottle, or else we could calculate the actual alkalinity demand.

http://www.kentmarine.com/pb.html

Let's guesstimate that it is similar to the alkalinity part of B-ionic in potency

http://www.esvco.com/prod6.htm

or about 2800 meq/L.

In that case, then a 16 oz bottle will contain about 1300 meq of alkalinity. In a 300 L tank, that's 4.3 meq/L per 10 days, or 0.4 meq/L/day.

That's not an unreasonable demand.

 

[tinycrazycrawler]

First, many many thanks for the answers. Now... the situation in my aquarium become every day more strange...
The story:
1/8/2002 new tank.
End of august beginning of the population.
Half september pink calcareus algae everywhere and the little acroporas growing very fast. Kh 8, Ca 450 *only KW added, from a Nielsen reactor in a quarium losing more than 1% water every day by evaporation* Mg 1150, ph 8---8,6 in the evening... To raise Kh of 1, was enough one spoon of baking soda.
For one month all the same. Lysmata and turbo spawning, hard and soft corals growing at a fast rate.
After, to kill No3 *5-10 in that days* I added 18 kg of aragalive from CaribSea. In one week No3 became not possibile to detect.
In a week KH became 5-6. I began to add Kh+. Kh goes to 7, and the day after is 6. The ph is 8 or more, also at early morning. In the last week I begun to add Mg, now is 1200.
The Ca begun to drop in the last days. Three days ago was 410, today is 350 (from two different testkits). Think that I use a fully operational Nielsen Reactor, with CaOh changed every week...
Where is all my Ca? And my Kh? All can be in the tissue of my acroporas, and coralline algae and a Calcareus Sponge that is growing everywhere? I belive to have understand "Yes" from the previous answers.
Now... what I can do? The only solution is to add a Ca-Co2 reactor?

Many thanks again!

 

[randy holmes-farley]

Sorry, I've been on vacation for the past week.

I can't really assess how much demand you have for calcium and alkalinity, but if limewater cannot keep up, then supplementing it with one of the two part additives is one route to delivering more. So is increasing evaporation with fans. So is adding some vinegar to the limewater.

So, of course, is adding a CaCO3/CO2 reactor, but I wouldn't assume that it is the only option.