Alk and Bleaching

[ataller]

I am new to reefkeeping so excuse me if this question has been covered before. I have a 30 gallon long reef, lit with a 4 bulb tek fixture. I run carbon, skim, and run chaeto in a HOB fuge mod. I keep many types of sps, lps, and zoas.

My ammonia is 0, nitrite 0, nitrate 0, ph 8.2, temp 79, calcium 400, and phosphate 0. I do weekly water changes with RODI and instant ocean.

A couple days ago I noticed my that most of my superman monti frag had started to STN, my clove polyps / duncans were closed, and my zoas seemed really light in colour. I checked my params and my alk was down around 5. Too low I know. It used to be 9.

I immediately added some baking soda that brought it back up to around 9. The next day it is back at 6ish.

First question, what is eating all this alk? The growing corals? Should they really be using so much? How do I keep it constant do I have to dose daily???

Second question, would the low alk cause bleaching? I have not changed anything with my light fixture. It is a newish upgrade, I have had it around 1 month now. Would it take that long to bleach my more sensitive corals.

My elegance, clove polyps, duncans, zoas, mushrooms and plate coral appear not bleached but they are lightening in colour. All acros, my montis, blastos, acans, torch, frogspawn, pocillipora and pavona all appear normal, great PE and great colour.

Thank you, hoping that I can stop whatever is happening.

Adam

 

[bertoni]

The growing corals can consume a lot of alkalinity, as can coralline algae. Many tanks require daily dosing. You might want to start dosing a 2-part, like B-Ionic. That's an easy way to get going. Over the long haul, a DIY 2-part or limewater might save some money.

 

[Todd March]

You have only 30 gallons with a lot of calcareous corals. As bertoni mentioned, daily dosing is going to be crucial. 2-Part, Ca reactor, kalkâ€"whatever works for you. But with only 30 gallons, I recommend something automated rather than just hand dosing; it's just going to get used up too fast. Remember, stability is one of the biggest keys to success, and stability is harder, IME, in smaller tanks...

 

[ataller]

I was thinking to myself the other day how well the tank was going, and how it pretty much took care of itself I guess I spoke to soon.

Ill look into getting some b-ionic. I suppose a calcium reactor would be the best way to maintain stability with the least amount of work. A reactor will have to come later on when I upgrade.


Thanks for the comments.

Adam

 

[Randy Holmes-Farley]

These article may help you decide what and how to dose the tank to supply calcium, alkalinity, and others, like magnesium:

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

The “How To” Guide to Reef Aquarium Chemistry for Beginners, Part 1: The Salt Water Itself
http://reefkeeping.com/issues/2007-03/rhf/index.php

The “How To” Guide to Reef Aquarium Chemistry for Beginners, Part 2: What Chemicals Must be Supplemented
http://reefkeeping.com/issues/2007-04/rhf/index.php

The "How To" Guide to Reef Aquarium Chemistry for Beginners, Part 3: pH
http://reefkeeping.com/issues/2007-05/rhf/index.php

The “How To” Guide to Reef Aquarium Chemistry for Beginners,
Part 4: What Chemicals May Detrimentally Accumulate
http://reefkeeping.com/issues/2007-09/rhf/index.php

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

 

[ataller]

Thanks Randy, I had purchased some Kalk before I set up the tank and never used it. I suppose using kalk in my ATO would be the best solution for me now from reading your articles.

Anyone with experience using Kalk and the Tunze Osmolator? I see that it is officially a no no, is that just legal mumbo jumbo?

Adam

 

[Randy Holmes-Farley]

I believe I've heard of many folks doing that and didn't know they recommended against it, but I'd double check with folks here or in the main forum to confirm that.