New To Reefing

TunaBlue

Member
Dec 16, 2014
156
32
Low Alkalinity In Cycling Tank.
hey guys, just tested my tank to see how my cycle is going and was hoping to do a water change and be able to add my live stock and well the results speak for them selfs... Advice please.

11/11/15
Salinity - 1.028
Ph - 8.4
Ammonia - 0.2
Nitrite - 0
Nitrate - 0
Alk - 7

14/11/15
Salinity - 1.026
Ph - 8.2
Ammonia - 0.4
Nitrite - 5
Nitrate - 0
Alk - 7

28/11/15
Salinity - 1.026
Ph - 8.2
Ammonia - 0.0
Nitrite - 0.5
Nitrate - 10

23/12/15
Salinity - 1.025
Ph - 8.2
Ammonia - 0.2
Nitrite - 0
Nitrate - 5
Alk - 4
 

Dean Lovett

Member
Apr 11, 2015
377
146
Penrith
Roughly speaking, alkalinity is a measure of the ability of your water to resist pH changes.

A drop in alkalinity, especially at your stage is likely due to the die off from the live rock and is a normal part of the process.

As the die off occurs, the rotting organic matter is acidic. These acidic ions then bond to the salts in the water that contribute to the alkalinity of the tank, thereby reducing the alkalinity in the tank, and thus eventually resulting in a drop in pH.

But like I said above, what you're seeing there in your tests is normal - and thankfully easily fixed.

All you need to add is some buffer, I use seachem marine buffer and it brings my kH up easily.

People with established tanks still need to monitor their alkalinity as like everything else it is dynamic and will likely require dosing.

So just add the buffer (as per the instructions on the bottle), wait 24 hours and test again. (Adding the buffer will get your pH to 8.3 and not above so you won't need to worry about that)

Btw, this is my opinion, I keep my salinity at 1.023, that way I have a bit of a safe zone if it goes a bit higher due to evaporation... Yours sitting at 1.025 doesn't leave the biggest safe zone if it were to climb a bit higher. I'd just suggest keeping a really close eye on it if you were looking to keep it at that level. (Especially if it is an open top tank with no auto top up system)
 

TunaBlue

Member
Dec 16, 2014
156
32
Should i do a water change to correct the problem and add the clean up crew ?
Thanks for that never read much into alk at this stage only the ammonia to nitrate cycle.
 

Agent M

Member
Oct 21, 2011
3,536
1,586
Melbourne
The tank has not completed its cycle, I would wait another 1-2 weeks, then do a decent sized water change and re-test after it has settled. I'd want to see 0 ammonia readings before I added any livestock.

I wouldn't be concerned about your alkalinity until you are ready to add coral. Then it is easily remedied with some bicarb soda dissolved in RO water if it is still low AFTER a water change. You shouldn't need to use an additive other than your salt mix for alkalinity if the tank has no corals or just a few in it. I've gone without it for years until this year when I got more coral (easy care soft corals and anemones).

For instructions on how to raise alkalinity with bicarb, follow this link and scroll down to Recipe #2 Part 2. http://thereefuge.com/threads/randys-recipe-maintaining-calcium-alkalinity-and-magnesium.376/
 

TunaBlue

Member
Dec 16, 2014
156
32
The tank has not completed its cycle, I would wait another 1-2 weeks, then do a decent sized water change and re-test after it has settled. I'd want to see 0 ammonia readings before I added any livestock.

I wouldn't be concerned about your alkalinity until you are ready to add coral. Then it is easily remedied with some bicarb soda dissolved in RO water if it is still low AFTER a water change. You shouldn't need to use an additive other than your salt mix for alkalinity if the tank has no corals or just a few in it. I've gone without it for years until this year when I got more coral (easy care soft corals and anemones).

For instructions on how to raise alkalinity with bicarb, follow this link and scroll down to Recipe #2 Part 2. http://thereefuge.com/threads/randys-recipe-maintaining-calcium-alkalinity-and-magnesium.376/
how long after the water change should i test?
The ammonia level was a bit iffy when i was testing it wasn't sure if it was 0 or 0.2, so i had the family do a vote lol.
 

Agent M

Member
Oct 21, 2011
3,536
1,586
Melbourne
how long after the water change should i test?
The ammonia level was a bit iffy when i was testing it wasn't sure if it was 0 or 0.2, so i had the family do a vote lol.
Just until the water clears. Sometimes water changes really stir things up or make the tank cloudy.

Lol about the vote! :D
 

Dean Lovett

Member
Apr 11, 2015
377
146
Penrith
Yep, as a colour blind reefer, the family vote is a must for me!

I agree with Agent M, wait the 1-2 more weeks - continue your water changes - I guess you could test like 2 hours after... That might be sufficient mixin time.
 

Lesley

Member
Apr 2, 2013
2,086
1,079
@Dean Lovett
See I am at the other end of the Salinity discussion. I think running in the middle at 1.025 is actually ideal, you have wiggle room both ways then.
can safely rise .02 if top up fails, but can safely drop 0.02 if you top up accidently dumps all you RODI in at once which I have had happen twice on the old tank.
I feel 1.023 is the lower end and would be worried if for some reason it dropped to 1.021-1.022.
I run my tank at 1.026 purely because the NSW I use comes in at 1.030 and its easier for me to dilute to that number.
 

Dean Lovett

Member
Apr 11, 2015
377
146
Penrith
@Dean Lovett
See I am at the other end of the Salinity discussion. I think running in the middle at 1.025 is actually ideal, you have wiggle room both ways then.
can safely rise .02 if top up fails, but can safely drop 0.02 if you top up accidently dumps all you RODI in at once which I have had happen twice on the old tank.
I feel 1.023 is the lower end and would be worried if for some reason it dropped to 1.021-1.022.
I run my tank at 1.026 purely because the NSW I use comes in at 1.030 and its easier for me to dilute to that number.
One of the main reasons I run 1.023 is because I don't have an auto top up - I do it by hand each night lol, but yeah there has been a few times where I have added a bit too much and the salinity drops a little to low, lol! Thankfully it's only happened those few times!
 

ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
The low alkalinity is a by product of the biological processes getting established in your tank. Never, ever do a water change when you're cycling a tank, you get rid of their food source and bacteria extending the cycling time considerably. You can bump the alkalinity up some, it's going to keep falling rapidly due to the acidification from the nitrogen cycle.
 

Agent M

Member
Oct 21, 2011
3,536
1,586
Melbourne
@Lesley @Dean Lovett You guys are keeping your corals within the recommended salinity range. Lesley if you dropped your salinity down to Dean's in a few seconds your tank would have no reaction whatsoever. Going up needs to be done more slowly but if you took it back up to your preferred salinity faster than recommended, I'd wager you'd see nothing as well. A lot of the advice you get is fail safe to ensure you have success, its not necessarily a hard and fast rule. Step outside of the acceptable range and you need to know what you are doing and why and for how long you plan on doing it.

You might find these articles interesting:
http://www.wetwebmedia.com/ca/volume_4/V4I4/hyposalinity/OST.htm
http://www.advancedaquarist.com/blog/the-effects-of-salinity-on-juvenile-rabbitfish
 

Agent M

Member
Oct 21, 2011
3,536
1,586
Melbourne
FYI @TunaBlue what I do for alk is put 2 level tsp of bicarb soda in a 2L bottle of RO water, shake it up and keep it on hand for raising my alk. I just put a little in at a time (1/2 cup maybe?) and test the next day to see where my alk is at. This is for a 180L tank.

I've noticed my zoanthids and sympodium are much happier since I've been doing this but no visible difference to my other corals, though I'm sure they appreciate it.


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Everything I say excludes SPS corals.