Long term stability

[Spschampion]

Hi reefing community,  My tank is about a year and a half old now. In that time I have learned a lot and spent a lot of money! Something I have struggled with, is long term stability. I can keep the big three(alkalinity, calcium, magnesium) really steady for 3 to 6 months. But, inadvertently something gets messed up. I test alkalinity every other day and calcium, magnesium, phosphate and nitrate weekly. Adjustments are made periodically to keep things even as possible. Water changes are done every other week to the tume of about 10%. I’ve put in a lot of effort to keep my alkalinity steady. I think it is within a 1/4 of a point DKH at all times. Every month or so I test alkalinity every two hours for a 24 hour period to try to detect any swings. Any tips on achieving rock solid elements long term? Just sucks when things get messed up. Almost always results in Acropora death! Thanx Pete

[albertareef]

Hi Pete,

I don't think there is any magic bullet here and everyone I know suffers from unexplainable swings at some point.  That said, there are folk on here who have been able to dial in some pretty impressively consistent numbers - at least with regards to the big three.  Both SuncrestReef and TheClark have been getting really tight numbers on their systems but they both are utilizing continuous (4-8 times a day) testing via their Tritons and have controls setup up to use that data to adjust either dosing rates or CA reactor parameters respectively.  This has resulted in something like 0.1 Alk unit swings over prolonged time - super stable.  Of course, this comes at the cost of an Apex and Triton setup plus integration costs.  I can't recall what size your tank is but that seems to be a common contributing factor as well - more volume means things happen more slowly so it's easier to catch and more inherent stability.  Obviously, that comes with it's own costs as well.  I have found the the hardest part is keeping nitrate/phos levels balanced.  These can be rock solid for months then one or the other will suddenly fluctuate with no apparent husbandry changes - super frustrating and often a precursor to other secondary problems (algae, cyan, Dino outbreaks).  I do believe that large refugium with a deep sand bed (or other bio equivalent) helps here but doesn't completely eliminate the problem.  Also, another promising avenue here is working on one's microbiome diversity.  Aquabiomics has started collecting a lot of data on microbiomes from many people's tanks and comparing the different bacterial spectra so there is hope that this will lead to recommendations on what the "best" profile might be for promoting stability with nutrient balance.  Still early there however.

Good luck!

[SuncrestReef]

Yes, as @albertareef said I have been using my Trident to both test frequently and to dynamically adjust my dosing throughout the day.  However, one thing you can do to help smooth out swings is to adjust your dosing schedule based on your lighting schedule.  Prior to using the Trident, I would test alk & cal once per day each morning at 9am.  My daily swings didn't look bad and I was pretty happy with it.  However, after setting up the Trident, I quickly learned how much the alk was changing throughout the day and night in between my daily tests:

The red dots show my manual testing schedule, and the orange is the automated Trident testing.  These daily swings are caused by the corals are soaking up way more alk during the afternoon and into the evening.  Compare the lighting schedule below with the alk for a single day:

To combat these swings,I adjusted my dosing schedule to add more when the lights were on, and less when off:

You said you occasionally test every few hours.  Have you determined what your daily swing looks like, and have you adjusted your dosing to compensate?

While I didn't directly address your question about long term stability, I believe more stable daily conditions contribute to longer term stability.

[Spschampion]

First of all thanks for the replys. My tank total water volume is about 100 gallons. Suncrest reef, I noticed something very similar to what you stated about alkalinity consumption During the photo period. I dose way more during the day then at night. Unfortunately, I have not employed a apex system yet. Would like to in the future. I’m sure that this is a way more accurate way to control additives. For now, I’m stuck with the old manual test and adjust. Albertareef, I am interested to see how the microbial balance effects the nutritional balance of our systems. Thanx again, Pete