Alk kind of whacky....

Fish Werx · Feb 24, 2017

OK. So, I have a 120g w/40 sump mixed reef.
temp - 78-80*f
SG - .026
pH - 8.1-8.2
NO3 - >2
PO4 - >.25
Calc - 440
Mag - ? ran out of reagents (advise if this is needed to remedy possible cause)

But my Alk has dropped to 6.5 from around 8 a couple weeks ago. Only thing I have added or changed is a colony (about 20 heads, large grapefruit size) of frogspawn, a few misc frags of zoas and 3 small (less than 3") frags of misc sps. I also started running chaeto in my sump about that time. All of that livestock I added may have added 5% to the amount of corals already in the tank btw.

I do a 20g water change each week.
I run gfo and carbon in a BRS reactor as per instructions from their site. I skim with a Reef Octopus 150 classic. I have chaeto in my sump with a regular lightbulb running opposite from daylights. It has doubled in size in about 2 weeks to a mass about a foot across.

I have a few frags of SPS, many med to large colonies of various LPS and quite a few nice size colonies and frags of softies. 2 clown fish, 1 fire fish, 1 melanurus wrasse, 1 lawnmower blennie, and 1 small Red Sea sailfin tang (and yes, we plan a major upgrade in tank size within about a year).

Corals seem to have nice PE and are open fully in the case of the softies and LPS. The only one that seems a bit less than happy is my Duncan colony, it is about 2/3 as extended as it usually is.

Should I dose some kind of buffer? Do you think it has anything to do with the new livestock in the tank? The reason for the questions is more because of the seemingly rapid decrease. I know any change should be slow and steady, just wondering if I should even worry about it? If I should, whats the best way to raise the Alk without throwing everything else out of whack?

Diesel · Feb 25, 2017

No buffer you need to dose ALK and CAL and MAG.
You need to do it slow though as you are a 6.8 that isn't bad yet but low enough to raise it.

Fish Werx · Feb 25, 2017

Diesel said:
No buffer you need to dose ALK and CAL and MAG.
You need to do it slow though as you are a 6.8 that isn't bad yet but low enough to raise it.

So in your opinion, would dosing Reef Fusion 1+2 at the recommended dosing be sufficient? And what about the added calcium?

I have ordered reagents for my MAG test kit, so hopefully that will be either part of the solution or taken out of the equation soon. If it is low, what would you consider to be the best dosing for that?
Ive always relied on my water changes to replace most of the elements in the water and it has served well for the most part. Usually the only thing i see fluctuate over time is Calcium.... And only by a very minor amount.
Thanks!

Randy Holmes-Farley · Feb 25, 2017

There should never be a "recommended" dose of alkalinity. A starting dose, perhaps, but not a fixed dose.

Any product dose needs to be tailored to the tank needs, and low alk is the first sign that you need to dose (or dose more) calcium and alkalinity.

Fish Werx · Feb 25, 2017

Randy Holmes-Farley said:
There should never be a "recommended" dose of alkalinity. A starting dose, perhaps, but not a fixed dose.

Any product dose needs to be tailored to the tank needs, and low alk is the first sign that you need to dose (or dose more) calcium and alkalinity.

Thank you Randy. I am starting the 1+2 dosing today at the manufacturers recommendation for the water volume I have just to get a base line on what difference it makes if any at this dose level. How often would you recommend I test for those parameters? Daily or is it more of a weekly thing to see a change?

Also, a friend gave me the link to your article on DIY homemade 2 part. I plan on reading that in its entirety and seeing if I can apply that to my system. So, double thank you!