Biocube 32 Alk solution

prokhk · May 4, 2022

Hi, I was wondering if anyone had any advice on how to manage my Alk in my biocube 32. This is kind of a long question so please bear with me.

I have noticed a decline in my alkalinity. I recently switched to a hanna checker from the api reef test kit two weeks ago. My alk read 8dkh on the api test kit, but read 6.9 with the hannah checker. It then dropped from 6.9 to 6.4 over the last two weeks. My torch coral and duncan are both struggling at the moment, with the duncan staying closed a lot and the torch bleached and lost two out of three heads. All the other corals including the other LPS I have seem to be doing fine.

In addition to the alk drop, my nutrients also bottomed out as I was out of town for two weeks and left the tank on an auto feeder and skipped a weekly water change. I usually supplement with frozen and reef roids which I think had been keeping the torch alive since it was bleached and also kept nutrients up. I had a bit of a hair algae bloom while I was gone as well.

Since I've been back I have done a water change and started feeding a bit heavier.

The tank is 6 month old, and as of yesterday my parameters were (all hanna checkers besides Mg):
Salinity: 32.2ppt
Temp: 25.4c
DKH:6.4
Phosphate: 0
Nitrate: 0
Ca: 445ppm
Mg: 1500ppm

My current stocking is as follows:
Two clowns
blue chromis
firefish
tailspot blenny

hermits (6ish?)
two trochus snails
a few nassarius snails

GSP
Several Zoas
Hammer
Torch
Long polyp leather
Gonipora
Duncan
clove polyps
ricordea muchrooms

All the corals are still somewhat small, but the Duncan and hammer had both been growing. Could that be the cause of the Alk drop? Would this be a good time to start dosing? I am also considering getting a tuxedo urchin and/or a conch. Is that a bad idea?

Is there anything else I should do to help with the alk or the algae?

TIA!

Lanny · May 4, 2022

I'm sure someone else will chime in, but yes it would seem dosing maybe in your near future.

In a "small" tank like a biocube you could easily use water changes to correct your alkalinity issue, as most salt mix brands mix to atleast 8.0 on alk. This will however reduce your nitrates. Feeding will help but can tend to add more phosphate than nitrate. You could dose nitrate, but that feels a bit radical for a 6 month system.

Personally I would start dosing alk until you approach the 8.3 to 8.7 mark and adjust from there. Some people don't like go below 8.3.

Most importantly don't raise your alk too fast. I don't like to do more than 0.5 dkh in 24hrs personally.

Good luck!

Randy Holmes-Farley · May 5, 2022

I'd look to begin dosing an alk and calcium supplement system of some sort (there are many good choices), and feed more or export fewer nutrients to be sure dinos does not become a problem.

prokhk · May 7, 2022

Lanny said:
I'm sure someone else will chime in, but yes it would seem dosing maybe in your near future.

In a "small" tank like a biocube you could easily use water changes to correct your alkalinity issue, as most salt mix brands mix to atleast 8.0 on alk. This will however reduce your nitrates. Feeding will help but can tend to add more phosphate than nitrate. You could dose nitrate, but that feels a bit radical for a 6 month system.

Personally I would start dosing alk until you approach the 8.3 to 8.7 mark and adjust from there. Some people don't like go below 8.3.

Most importantly don't raise your alk too fast. I don't like to do more than 0.5 dkh in 24hrs personally.

Good luck!

Thank you! Yeah I will start looking into dosing options. I kind of like the idea of a dosing pump so the tank can be a bit more self sufficient. I may turn off my protein skimmer for a little while and see if that helps. I will definitely go slow adding alk, thanks for the heads up!