HELP! ALK keeps dropping!

[VJV]

Thanks Randy! I do not have baking soda but do have Seachem Reef Buffer and Red Sea Alk buffer supplement. The reason I was more inclined to the water change method was because I am afraid that if I dose anything it will precipitate again. In the other hand, a large water change with Red Sea Pro salt which has an Alk of 12.2 might be too much and to fast change and damage the corals...?

 

[bertoni]

With the dKH that low, the amount of precipitation is going to be tiny unless the supplement goes into a very small volume of water. I'd just dose into the main tank.

 

[VJV]

I am dosing in the return chamber of my sump. It Is a small section where the return pump is (60 watt Eheim compact 3000+) which puts out some heat. Could this be a reason for the precipitation? I know it is a small section of the pump but on the other hand the dosing should be quickly sucked by the pump.

The other thing I have in this chamber is a closed loop 18w UV. Given that the dosing tubes are almost above the return pump I guess nothing is being sucked into the uv, but can not tell for sure. The uv pump sits in the opposite side of the chamber and is much smaller, and set for very low flow (some 130L per hour).

 

[bertoni]

Dosing into a small chamber might cause problems. I'd dose into the main tank.

 

[VJV]

So, an update!

19/09: Alk was at 5,2 dKH. That was roughly 0,3 dKH drop in 4 days so started dosing 8ml of buffer, daily.

20/09: Alk at 5,37 dKH. Nice! Made a 35% water change (measured 11,4dKH)

21/09: Alk now at 7,2 dKH. Increase daily dosing to 33ml per day in order to increase 3,0dKH over the next 3 days. Programmed the dosing pump to split the dosage by 12 times per day, in order to avoid a sudden increase that could lead to precipitation.

Will report back in 3 days.

 

[bertoni]

Okay, that sounds like good progress.

 

[VJV]

24/09: Alk tested at 8,52 dKH...

It should be at 10,2 dKH! It seems that with the increased dosing I am back to having precipitation??? Or is it because above 7.0 dKH the uptake of Alk is much higher...???

I will keep this dosage and see how it evolves. Meanwhile today (25/09) did a 40% water change so will test again later wait 3 days and re test to see what was the change.

 

[bertoni]

As the alkalinity level increases, the consumption will tend to increase, if there's enough food and light.

 

[VJV]

HELP! ALK keeps dropping!

Thanks! Will test in two days again to see what is he uptake. In the meanwhile I sifted all my sandbed and removed all clumps. After I increased buffer dosing immediately small crumbs started to appear in the sandbed. Thy are easily crushed with the fingers but I wonder if this is a sign of precipitation?

Post water change levels:

Alk: 9,6 dKH (reduced daily dosage to 25ml which should equate to a 1.0 dKH increase per day.

Calcium: 432ppm

Magnesium: 1440ppm (stopped dosing)

 

[toothybugs]

Thanks Randy! I do not have baking soda but do have Seachem Reef Buffer and Red Sea Alk buffer supplement. The reason I was more inclined to the water change method was because I am afraid that if I dose anything it will precipitate again. In the other hand, a large water change with Red Sea Pro salt which has an Alk of 12.2 might be too much and to fast change and damage the corals...?

Just as an aside, next time you buy groceries look for baking soda. I picked up a 3lb box of Arm&Hammer for about 4 bucks from my grocer. It's the only thing my tank consumes regularly as my calcium and mag levels drop slowly but my alk drops a few values every week. I got in the habit of putting 2 tbsp in my 5gal top-off water and the tank stays within 0.1dKH every week.

 

[bertoni]

I am not sure what the "crumbs" are, but I wouldn't worry yet. Even if they are precipitate, the rate might be acceptable.

 

[VJV]

By crumbs I mean like small pieces of sand crumbs forming.

26/09: as per previous post did a large (35%) water change the day before. Post water change Alk is at 9.63dKH. Reduced dosing to 24 ml per day.

28/09: Alk tested at 8,62dKH... a 1.0dKH in two days. Given that the 24ml daily dosage should increase dKH by 1.0dKH, that means actual consumption is around 1.5dKH per day.

Did not change the dosage and will test again next Friday to see where it is. I do not have a lot of experience but this in a tank that has no fish in for the past 3 months, and only 7 LPS corals...? Why such a high consumption of Alk?

 

[VJV]

Just as an aside, next time you buy groceries look for baking soda. I picked up a 3lb box of Arm&Hammer for about 4 bucks from my grocer. It's the only thing my tank consumes regularly as my calcium and mag levels drop slowly but my alk drops a few values every week. I got in the habit of putting 2 tbsp in my 5gal top-off water and the tank stays within 0.1dKH every week.

Thanks! Being a bit of a novice I am a bit reluctant in going DYI here... I will probably end up there but for now I feel more comfortable dosing additives such as this Red Sea that carry very precise instructions on how to dose and what to dose based on your tank parameters. I am probably wrong, but for now until I have a greater grasp of what is going on in my tank I guess I will stick to this.

 

[bertoni]

If the crumbs redissolve with a bit of water motion, they probably are magnesium hydroxide, which is fine. This article might help:

http://reefkeeping.com/issues/2005-07/rhf/index.htm#6

 

[VJV]

HELP! ALK keeps dropping!

The crumbs are just bits of sand stuck together, like little rocks. They are small and easily break with fingers, but it does seem like early consequences of precipitation.

 

[bertoni]

That might be precipitation, or it might be bacterial action. Both are common, IME. You could switch to baking soda. It will be lower in pH, which likely would reduce precipitation, if there is any.

 

[A. Grandis]

I don't know exactly why, but I had those crumbs only when adding kalk in the past, looong time ago.

Today I dose a bit of kalk for coralline algae, no hard corals, and also BRS buffer for the alkalinity. I believe if I use only kalk to maintain alk will have a negative effect because of the low consumption of Ca++.

Would the type of sand have anything to do with those crumbs' formation?
I use Oolitic sand CaribSea.
No problems at all...

It's interesting 'cause I totally forgot about those things, hard to fully understand how that happens. I can find some in the ocean as well...

Grandis.

 

[VJV]

Thanks, I suspect there may be some kind of interaction between the sand and the Buffer. The sand is TMC fine grain aragonite sand. I just find strange to have such large consumption of Alk in a 80gallon tank with so little corals, but maybe this is just the way it is. I will measure again Friday and increase the dosage to 48ml daily, divided by 24 dosings.

 

[evan38109]

I don't know if this is on the right path, but here's a thought:

I noticed that you mentioned using buffer products like Seachem Reef Buffer. As I understand it, those generally contain a combination of chemicals intended to partially-kinda-sorta cancel each other out in ways that keep constant parameters. (Google can explain the chemistry better than I can.)

Plenty of unintended reactions can occur. At the extreme, if one part of the buffer is reacting with something unidentified, Weird Things may happen. I would only reach for a buffer if I had severe pH problems.

Have you tried using the plain alk supplement from a good 2-part mix, or simple baking soda (preferably baked -- search for related threads)?

Again, I'm no expect, just thinking this through...

 

[bertoni]

[welcome]

Buffers generally are high-pH alkalinity supplements. They work by consuming carbon dioxide from the water column, basically. Unfortunately, aeration will bring carbon dioxide back into the water column, so the effects generally are short-lived, so buffers generally don't help much.