Neptune Aquatics

Alk consumption gradually decreasing ..

newfly

newfly

Supporting Member
BARcard
I can’t seem to find the problem. Parameters are within range

Alk 8.5
Cal - 450
Mag - 1400
Salinity - 1.0025
Nitrate 5-10
Phosphate 0.05

I know my ca and mg is a little of high side but it’s been like that forever.

I was dosing 100ml of soda ash for months and out of the blue, my alk consumption overnight drop to 80ml. Then it held steady for a month or two, and then start dropping again slowly ( like 0.1dkh a day) I’m now at 70ml for 65g tank. Alk have been stable since I adjust the dosing every day.

Lost 2 small tiny frags over the past several months. Looking ok and suddenly turn white the next day. Now a med size frag showing sign of stress.

I have been doing 30-40% water change weekly to help stabilize things. I think it’s a bandage . Something is off and I can’t seem to find the problem.

Just send out the ICP test.

I’m lost. Bad batch of salt or chemicals (soda ash, etc)?
 
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Dosing is easy to assess. Take some saltwater, measure alk, use the BRS calculator on how much you need to raise it by X amount. Add X amount. See how close you get.

If you're saying consumption is decreasing, the most obvious answer would be corals not growing as fast as before. Is that happening?

Other options include GFO or other things getting fully consumed and no longer sucking up other things (which tends to include alk).
 
I am dosing and have been adjusting daily because of the reduce consumption. Alk have been consistent because of my daily adjustment.

I can’t tell if the coral is growing slower.

GFO is a good point. I did put some GFO to drop the phosphate from 0.2 ish to 0.05 now .

One smallish coral is obviously stressed. Turning white from the base. Majority of the corals looks ok to me.

I’m mixing water now for a 50% wc while waiting for icp.

I did however put my hand in the tank every other day for past months to remove bubble algae. I usually wash my hand before doing that. Maybe some contaminants get into the water . I’ll change out the carbon just in case
 
Ph varies through the days as we have visitors staying over and with the cold weather most windows are closed. Low 7.7-8.2 high
 
dangalang said:
Maybe the GFO sucked up too many trace elements and the corals didn't like it, so they are stalling/slowing their growth? Be interesting to see what your ICP says.
Click to expand...

I am also in camp GFO. If it is true that it (significantly) reduces trace elements, then this sudden removal should impact the corals' ability to photosynthesize, hence their alk consumption until this is adjusted. Some of the traces (e.g., fluoride) seem to protect corals from the negative impact of intense lighting so if this is being removed, it stresses the corals.

In summary, GFO seems to be a cheap way to address high phosphate issues but I would not use it for the above reasons, and rather go with a thought out dose of lanthanum (which also has downsides), or my preference is Elimi NP/aka carbon dosing from Tropic Marin (and/or more frequent water changes).
 
As a clarification: my mention of GFO wasn't towards GFO as a boogieman causing bad coral growth, but more simply that GFO consumes alkalinity. If you replace your GFO with fresh ones, presumably it'd more quickly suck up alk. After awhile, as it gets bound, it'll consume less to eventually none.

Not saying that's occurring here, but could be.

If you're seeing corals struggling though, sounds like it'd be highly plausible lower coral growth rates and you're seeing it as alk changes.

More on GFO + Alk: https://www.reef2reef.com/threads/why-does-gfo-decrease-the-alkalinity.683222/
 
richiev said:
As a clarification: my mention of GFO wasn't towards GFO as a boogieman causing bad coral growth, but more simply that GFO consumes alkalinity. If you replace your GFO with fresh ones, presumably it'd more quickly suck up alk. After awhile, as it gets bound, it'll consume less to eventually none.

Not saying that's occurring here, but could be.

If you're seeing corals struggling though, sounds like it'd be highly plausible lower coral growth rates and you're seeing it as alk changes.

More on GFO + Alk: https://www.reef2reef.com/threads/why-does-gfo-decrease-the-alkalinity.683222/
Click to expand...
Suggestion as a test:
1. Water change, see if coral gets better. If so, could be the water is missing something, or could be bad juju in the water (add some carbon media)
2. Partial gfo replacement, see if alk usage increases. Careful not to bottom out your phosphates

Also, always a good opportunity when something is weird in measurement is proactively get a new kit for measuring that. Eg Hanna packets expire after unsealing the plastic (I'm not sure how quickly)
 
richiev said:
Suggestion as a test:
1. Water change, see if coral gets better. If so, could be the water is missing something, or could be bad juju in the water (add some carbon media)
2. Partial gfo replacement, see if alk usage increases. Careful not to bottom out your phosphates

Also, always a good opportunity when something is weird in measurement is proactively get a new kit for measuring that. Eg Hanna packets expire after unsealing the plastic (I'm not sure how quickly)
Click to expand...
Thanks. That’s what I did

1. 2 x 40% water change today
2. Remove GFO all together + change the carbon.

I also clean out the coralline encrusted flow pump. This might impact the Alk a little.

The Alk is consistent with Hanna and Alkatronic , I assume I can trust the number . Due to the massive water change, I can’t measure the alk consumption today. I’ll report in a couple of days to see if the trend change. .
 
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My huge sentosa colony (12" across) started peeling at certain spots. Another crash? Last one was a few months ago. this might be the sign to give up on SPS. Might just turn the tank into zoa and other soft corals. I'm getting burned out.
 
Coral reefer said:
You’re doing huge water changes with nutrients near zero. It’s a dangerous place to be imo
Bummer you’re struggling!
Click to expand...
this come across my mind, but since i only did the water change yesterday, i don;t think 24hours of low nutrients will cause the coral to start peeling . But who knows. i'm letting the tank as-is for now. I think more changes is detrimental when i'm shooting in the dark.
 
Alexander1312 said:
I am also in camp GFO. If it is true that it (significantly) reduces trace elements, then this sudden removal should impact the corals' ability to photosynthesize, hence their alk consumption until this is adjusted. Some of the traces (e.g., fluoride) seem to protect corals from the negative impact of intense lighting so if this is being removed, it stresses the corals.

In summary, GFO seems to be a cheap way to address high phosphate issues but I would not use it for the above reasons, and rather go with a thought out dose of lanthanum (which also has downsides), or my preference is Elimi NP/aka carbon dosing from Tropic Marin (and/or more frequent water changes).
Click to expand...


richiev said:
As a clarification: my mention of GFO wasn't towards GFO as a boogieman causing bad coral growth, but more simply that GFO consumes alkalinity. If you replace your GFO with fresh ones, presumably it'd more quickly suck up alk. After awhile, as it gets bound, it'll consume less to eventually none.

Not saying that's occurring here, but could be.

If you're seeing corals struggling though, sounds like it'd be highly plausible lower coral growth rates and you're seeing it as alk changes.

More on GFO + Alk: https://www.reef2reef.com/threads/why-does-gfo-decrease-the-alkalinity.683222/
Click to expand...

GFO removes alkalinity -> appears like higher uptake.
GFO steals trace elements, reduces growth rate -> appears like lower uptake

These are opposite effect

The iron in GFO likely causes the alkalinity to precipitate out. Not sure if the GFO being spent would impact its ability to cause this to happen (not sure if it would cause decrease in “consumption” once it’s saturated)

Since you removed it I’m not sure this matters anymore though

If your nutrients are low, I really suggest bringing them up at least a little. Feed more or dose them until normal range is reached.

If all go your parameters are testing within range, and are not changing quickly, I’m wondering what else could be the problem. Temp fluctuations? Slight stray voltage? Chemicals? Could magnets have cracked? Maybe ICP will help if it happens to be one of these things
 
Maybe last pretty picture for the tank.
 

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