Tank Growth "stall"- Possible causes?

[tigé21v]

Not sure if this is the right forum to post this. If not, Mods please move.

In a matter of less than a month my system went from using north of 2 1/2 gallons of kalk a day to needing no supplementation, and only consuming about 1-2 ppm of alkalinity daily. Growth pretty much seems to have stopped overnight.
The only change I made to the system is I decided to try to clean up my Rubbermaid sump, and put a power head in there to stir things around a bit and started running around 150-200 gph of sump water through a 10 micron sock 24/7. The sump wasn't in that bad of shape, I had cleaned it out via a water change a couple of months ago. I was changing out a 7x14 sock every three or four days. System volume is 450+/- gallons.
I was into it for a few weeks, maybe a month, when things went south.
By the time I realized something was out of whack, alkalinity had risen from a rock-solid 127ppm to 16ppm over the course of little over a week. Which, of course, has led to tip burn on any acros, and even had my stylo colony looking so ragged I gave it away so I wouldn't lose it.
I had noticed my ph was slowly climbing, but nothing dramatic. Maybe an average of 0.1 over the course of a month. ORP was more noticeable, probably a 10-15% rise.
So, I'm left wondering..
Did the constant removal of junk from the water column allow the alk to rise, since there was less stuff in the water decaying?
Or, was the constant removal taking out all the food present in the water column, so the corals started to starve, and that's what stopped the growth?
The tank is fed heavily, daily. Pellets in an auto feeder throughout the day, a sheet of nori or more, and at least a 1"x1"x1" cube of frozen.

Any insight is appreciated.
TIA

 

[Flippers4pups]

Not sure if this is the right forum to post this. If not, Mods please move.

In a matter of less than a month my system went from using north of 2 1/2 gallons of kalk a day to needing no supplementation, and only consuming about 1-2 ppm of alkalinity daily. Growth pretty much seems to have stopped overnight.
The only change I made to the system is I decided to try to clean up my Rubbermaid sump, and put a power head in there to stir things around a bit and started running around 150-200 gph of sump water through a 10 micron sock 24/7. The sump wasn't in that bad of shape, I had cleaned it out via a water change a couple of months ago. I was changing out a 7x14 sock every three or four days. System volume is 450+/- gallons.
I was into it for a few weeks, maybe a month, when things went south.
By the time I realized something was out of whack, alkalinity had risen from a rock-solid 127ppm to 16ppm over the course of little over a week. Which, of course, has led to tip burn on any acros, and even had my stylo colony looking so ragged I gave it away so I wouldn't lose it.
I had noticed my ph was slowly climbing, but nothing dramatic. Maybe an average of 0.1 over the course of a month. ORP was more noticeable, probably a 10-15% rise.
So, I'm left wondering..
Did the constant removal of junk from the water column allow the alk to rise, since there was less stuff in the water decaying?
Or, was the constant removal taking out all the food present in the water column, so the corals started to starve, and that's what stopped the growth?
The tank is fed heavily, daily. Pellets in an auto feeder throughout the day, a sheet of nori or more, and at least a 1"x1"x1" cube of frozen.

Any insight is appreciated.
TIA

Have you tested your other water pramameters? What's your N03 and P04 at?

Any other changes recently?

How are you testing alkalinity? What kit?

 

[Troy V]

How old is your system? And I am curious what your PO4 levels are at?
When things in my tank stop growing its usually when my PO4 is out of an acceptable range. As your system ages, and you feed regularly it is common for your PO4 levels to creep up and effect calcification. I normally add a 1/4 of the recommended amount of high capacity GFO, and after 2 weeks do a 20% water change. This usually gets the tank back on track for me. Good luck

 

[Flippers4pups]

How old is your system? And I am curious what your PO4 levels are at?
When things in my tank stop growing its usually when my PO4 is out of an acceptable range. As your system ages, and you feed regularly it is common for your PO4 levels to creep up and effect calcification. I normally add a 1/4 of the recommended amount of high capacity GFO, and after 2 weeks do a 20% water change. This usually gets the tank back on track for me. Good luck

Could be that or the other way around, no P04.

 

[Blackice615]

I feel like I'm struggling with this myself. I used to leave home for a week and come back to crazy growth. Now....tank is the same as when I left

 

[tigé21v]

Have you tested your other water pramameters? What's your N03 and P04 at?

Any other changes recently?

How are you testing alkalinity? What kit?

NO3 5ish, PO4 .03 or so
No other changes at all
Part of the reason I had slacked bit on checking alk.
Didn't think running a filter sock would have such an impact

(Hanna, checked against two different reagents, within 1ppm of each other)

 

[tigé21v]

How old is your system? And I am curious what your PO4 levels are at?
When things in my tank stop growing its usually when my PO4 is out of an acceptable range. As your system ages, and you feed regularly it is common for your PO4 levels to creep up and effect calcification. I normally add a 1/4 of the recommended amount of high capacity GFO, and after 2 weeks do a 20% water change. This usually gets the tank back on track for me. Good luck

It's been 10 years since I bought the main system from a fellow reefer, who had it running for probably 10 years before me.
I've added here and there over the years, but nothing as of late.

 

[Flippers4pups]

Okay, kalkwasser in your ATO reservoir?

 

[tigé21v]

No. Peristaltic pump. Total control.
I can raise or lower my alk by 1ppm a day if I want.
(Well, I WAS able to....)

 

[Flippers4pups]

No. Peristaltic pump. Total control.
I can raise or lower my alk by 1ppm a day if I want.
(Well, I WAS able to....)

Possible over dose at some point, especially if you weren't testing on a regular basis?

 

[tigé21v]

Possible over dose at some point, especially if you weren't testing on a regular basis?

No.
Rock solid. Controlled via Apex.
Check the output every month or so.
"Overdose" came as I tried to cut back on dosing. Chased it for over a week, cutting back and daily and still gtting higher readings. Should've shut it off for 24 hours as soon as I had a rise in the alk.

 

[Flippers4pups]

Okay, like you originally stated, something has caused the "growth" stall. Water contaminants, temp.....etc.

If alkalinity rose because of lack of growth, then calcium should have stalled too.

 

[tigé21v]

Okay, like you originally stated, something has caused the "growth" stall. Water contaminants, temp.....etc.

If alkalinity rose because of lack of growth, then calcium should have stalled too.

I didn't check calcium since it started, not too worried about it. It was 420 before it began. Alk didn't get high enough, and my ph never gets high enough, to need to worry about a precip event