Solving an Alkalinity swing problem in a nano tank

[reeferfoxx]

@n2585722 Are you familiar with the reefkeeper? Can you help in this department?

 

[n2585722]

Ha! That is a clever explanation! Admittedly, I'm not a Reefkeeper expert when it comes to the programming...

So, each dosing pump is on its own outlet and each is set to a simple timer:
Day of the Week:SMTWTFS
Start time: 12:01am
duration: 34 seconds
Time off: 29:30
Repeat: 48
Oscillate: off
Random: No.

The other pump On time is 12:05am, same program.

I think it's okay. Although I need to check exactly what the oscillate and random settings do.

If your time the timer is active goes over 24 hours it will not trigger until the next start time after timer is no longer active. This can make it skip a day of dosing. To me it looks like that will go over since on time and off timer add up to 30 minutes and 4 seconds
Also it will cycle 49 times unless you have a Archon and not 48. The first time through in not in the repeat count. Take 4 seconds off of either on time and off time and set repeat to 47. I still don't like having it that close. If you could take 5 seconds off it will finish 48 seconds before it is to start again. If for some reason the controller resets during the day it will not start dosing again until the start time passes. If you have a RKE I think you can split the dosing up into 4 timers for the day using the multi-timer function. On the RKL it would be 2. The Archon it would be 3. This would prevent you from missing a whole day of dosing.

I will see if I can come up with a example. I used to have several at one time. Hope this helps.

 

[natickwaterbox]

Wow, I seriously hope that is it!!! Makes sense to me. You guys are clever! I will adjust the timer according to n2585722 and reeferfoxx's suggestion.

I'll report back once I'm confident the issue has or has not been resolved.

 

[natickwaterbox]

@n2585722 Just for simplicity and ease of testing... if I were just to reduce the repeat# to "46" but keep the program the same that should keep me under the 24 hour maximum duration and solve the problem if this issue is the underlying cause. Yes?

 

[n2585722]

@n2585722 Just for simplicity and ease of testing... if I were just to reduce the repeat# to "46" but keep the program the same that should keep me under the 24 hour maximum duration and solve the problem if this issue is the underlying cause. Yes?

Yes

 

[rosshamsandwich]

lowering your light period helps ...

 

[KTTX]

IMHO, I think you should try not doing daily water change and check the alk for 3 days to see if you have same issue. This to me is most likely contributing to this issue.

 

[n2585722]

natickwaterbox, did the change in programming help any?

 

[natickwaterbox]

Update:

So, I changed the program a bit from what we discussed above because my Alk swung up to 9.6 dKh during late in the 12-hour light cycle. The new program is:
Day: SMTWTFS
Time On: 12:01am
Duration: 33 seconds
Time off: 29:30
Repeat: 45
Oscillate: Off
Random: No.

I installed a new pH Probe and calibrated it using 7/10 standards.

Then I monitored dKh over a 43 hour time period to test whether "the cycle" was still there:
Lights are on 10:15am - 10:15pm
Day 1 10pm: 7.96 dKh / pH 8.11
Day 2 8am: 9.30 dKh / pH 8.03
Day 2 5pm: 9.1 dKh / pH 8.2
Day 2 11pm: 8.85 dKh / pH 8.1
Day 3 7am: 9.4 dKh / pH 8.01
Day 3 5pm: 9.07 dKh / pH 8.23

The cycle is gone. Bravo gentleman - it certainly was a programming problem - thanks a lot!

Alkalinity is now a little higher than I would like it to be so I am going to step down 2 seconds at a time until I hit ~8 dKh level.

It's interesting that the corals were able to not only tolerate this type of swing but that some of the SPS Acros in there actually thrived (tons of new growth).

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for the update!

 

[n2585722]

Thanks for the feedback. Glad we could help.