HELP! ALK keeps dropping!

VJV

VJV

New member
Hi, I would really appreciate if I could get some help on this. I have a 6 months old 80 gallon tank. I use Red Sea Coral Pro salt and Rd Sea Reef Foundation sure nets for Alk, Calcium and Mg. Currently still only have about 8 LPS (hammer, frogspawn, elegance, cats, lobo,) and couple of softies. I want to add SPS but do not want to do it as my parameters seem a bit wacky. My Mg stays relatively stable at 1250-1300, my Cal drops 8ppm per day which I believe is normal. My Alk however, drops some 2.0 dKH per day!!!?!?? Have been dosing 50ml per day of Red Sea buffer supplement for the past 4 months but Alk continues to drop like a stone!?

Not sure if related, but since I am dosing such a high amount of buffer my snails do not seem to far to good.

Also, another strange chemical reaction that is happening in my tank is that the sand bed keeps hardening. It's a hard crust that in some parts is rock hard. I guess this must be due to some kind of calcium precipitation though as noted above Calcium is actually relatively stable. Could this be elated to the Alk issue?

A lot of questions but I have the feeling that are probably interrelated so here is my cry out for help to the experience refers here in Reef Central!

Thanks!

https://vimeo.com/105355616
 
Sounds like you are over dosing. The calcification/precipitation on the sand bed is consuming the alk. I would stop dosing for a while. For those types of coral the RSCP is probably adding more than enough. Let things stabilize after several water changes. Then measure the drop over several days to determine a good starting point for dosing. You may not need to dose yet. I don't dose anything for my softy tank. Just water changes. Coralline grows like crazy.
 
2 dKH per day is well within the possible range of a tank's consumption. My soft coral tanks went through 2-3 dKH per day due to coralline algae growth. I'd expect a drop of around 16 ppm of calcium per day, but that can be skewed by water changes and test kit noise.

Which buffer product are you dosing?
 
Thanks for all the replies! I am dosing Red Sea Reef Foundation B, and A, Alk and Cal. I have been dosing according to the measured consumption over a 4 day period. Calcium has stabilized but Alk consumption keeps growing. I believe my snails are dying due to the sudden 2.0dKH change due to the dosing of 50ml of Reef Foundation B (Alk). Could this be it?

Regarding the sand, I also thought it would be precipitation but why is calcium not dropping too much? Whatever it is the truth is the sand keeps creating a crust.

I will stop dosing and report back.

Thanks!
 
Thanks! I do agree that precipitation is probably the most likely culprit for the hardening of the substract, but a couple of things puzzle me after reading these articles:

1- I have no visible precipitation on pumps, heaters, or any other such items...
2- of course this might be a consequence of precipitation, but after 6 months I still do not have Coraline algae in the tank, in spite of maintaining high levels of Calcium.

On two, it must be said that the tank was aquascaped with ceramic rock from Aquaroche and the only pieces of live rock are the ones attached to the corals.

One other thing, what do I do if Alk falls below 7.0dKH?
 
If the alk drops below 7 dKH, I'd use the two part to supplement it. :)

A number of folks seem to use a large amount of additives to maintain normal readings. We've never really understood exactly why, but precipitation into the sand is one sink.

have you ever measured pH in the tank? If the ceramic rock is cement based, it may boost pH and increase the likelihood of precipitation, especially locally to it.
 
Hi Randy. The ceramic rock I believe is not cement based. It is highly porus and acts as live rock once colonized. Here is the website: www.aquaroche.fr. My PH is usually in the 7,8-8,0 range, so quite low.

The Red Sea Reef Foundation is actually a 3 part, but I have never dosed Magnesium since levels seem to be steady. I wonder if dosing even if just 1ml per day of Mag would help "bind" calcium carbonate and reduce precipitation...?

One other thing: been thinking about adding a sea cucumber (holothurus) to keep the sandbed clean and stirred, but am afraid that the clumps that I currently have would damage the holothurus internal organs, and potentially kill it. Would you say it is ok to add or would I need to take all the clumps out first?

Thanks!
 
I try to keep my alk with weekly water changes and BRS alk daily dosing. Kalk is added for the coralline algae too, but very very tiny amounts!!! I have no hard corals. Got oolitic sand and never had problems. I would brake the clumps with fingers and do only water changes for like 3 weeks or so to give the system a rest. Then you go and dose a 2 part very slowly and testing to see what your system is using. I don't think you'll have any problems adding the Holothuria sp. now.

Go very slow with dosing. Your tank is way too young!!!!
You don't need that much.

Grandis.
 
VJV said:
The Red Sea Reef Foundation is actually a 3 part, but I have never dosed Magnesium since levels seem to be steady. I wonder if dosing even if just 1ml per day of Mag would help "bind" calcium carbonate and reduce precipitation...?

!
Click to expand...

Seawater already has a huge amount of magnesium in it, so adding a small amount is unlikely to make any difference.

100 gallons of seawater has more than a pound of actual magnesium, which would take a huge amount of most additives since magnesium is necessarily a small fraction of even a dry magnesium supplement.
 
Thanks! When I get home tomorrow I will test for Alk, Calcium and Magnesium, and repeat 3 days later to see what is the actual consumption and post back.
 
By the way, I have been using Red Sea's pro tests for these elements, and recently purchased Hanna Checkers for Alk and Calcium. Alk readings in the Hanna are similar to what I get with the Red Sea one, but Calcium seems to be 100ppm higher. Not sure which trust given I read a lot of bad reviews on the Hanna Calcium test (even though some people do seem to be capable of getting accurate readings), but on the Red Sea titration test I am always not sure where to stop the titration (and yes, I have seen the videos).
 
VJV said:
on the Red Sea titration test I am always not sure where to stop the titration (and yes, I have seen the videos).
Click to expand...

I called red sea way back when the kit first came out about the same question as you. They said ...."Keep adding drops until the sample stays blue and does not turn back at all to even a hint of blue/violet"

I've been using the calcium pro since it came out. It takes a bit of practice to get the hang of it. It may take 15-20 seconds of shaking to be sure the sample stays completely blue.
 
An update:(measured with hanna checkers and checked with Red Sea Pro calcium test kit)

Yesterday:

Alk: 5,88dKH 😳😳😳
Cal: 450ppm
Mg: 1340ppm

Have not add anything and will repeat in two days prior to water changes.
 
So, measured again today and it read as follows:

Alk: 5,48dKH
Cal: 437ppm

So, over 3 days Alk dropped 0,4, or 0,13333dKH per day. This clearly demonstrates (I guess) that before I was getting tons of precipitation, as I was adding the equivalent to 1,4 dKH daily and still the Alk was dropping.

I now started dosing Alk daily to cover for the 0,133 daily drop. Next weekend I will perform a couple of large wat changes to start bringing the dKH value back to 11dKH.
 
The reason the alkalinity is dropping so slowly is that growth slows down and eventually stops as the dKH drops below 6.5 or so. That's why it's best to measure and dose each day.
 
Thanks, did not know that. Well, next weekend will try to perform a couple of large water changes to bring Alk level up.
 
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