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Alkalinity concerns

For the past few months I’ve had no problem keeping my alk and calcium at the proper levels. I could manually dose my tank 5 ML of alk and 3 ML of calcium a day and my levels would be around 8.3 and 420.

Than last week I went on a weeks vacation and my stepdaughter looked after my tank for me. I taught her how to dose and feed the fish and thought all would be well.

When I got home on Sunday my skimmer was overflowing for unknown reasons and when I tested the water my alk was 7.2 and calcium was 400. I thought no big deal and dosed my tank with a little extra alk. 8ml to be exact. I tested the water the next day and it was at 7.2 I than did my 10% routine weekly water change and dosed the tank with 5ml of alk and 3 ml of calcium. I let the tank sit for about 5 hours and tested it again and it read 7.5 for my alk. The calcium was at 420 which is where it should be. I than dosed my tank with 8ml of alk and tested it this morning. It read 7.5 again. So I did my daily dose but this time I gave it 10ml of alk hoping to get it back to 8.3 I let the tank sit for about three hours and when I came home I tested the alk again and it now read 7.7. Knowing something is wrong I changed the batteries in my Hannah alk tester and tested the alk twice and it keeps reading 7.7

I don’t want to overdose my tank and don’t know what to do. Why is it absorbing so my alk without raising the alk levels to where they use to sit?

Has anyone ever experienced this before??? Any help or advice is much appericiated.
 
Do you have access to a secondary testing kit? Salifert maybe? How big is your tank? Are you dosing Alk and Cal at the same time? Do you have a lot of stony corals? LPS/SPS
What dosing supplement are you using?
 
I dont have immediate access to a different test kit. My tank is a 65 gallons with a 29 gallon sump. Total water approximately 80 gallons. No I don’t dose at the same time. I usually wait about 15 minutes in between dosing alk and calcium. My tank is mainly lps, soft coral, mushrooms and zoas. No sps at all in my tank. I use Red Sea alk and calcium supplements and have been doing so for the last two years. Along with Brightwell salt mix.
 
if you are using Red Sea Alk 4ML would barely touch your levels. If you want to actually bring the levels up you will need to dose at least 30ml in a day. That will bring you up roughly 1 DKH.

Per the instructions 10ml for 25g will increase 1dkh so x 3 for roughly 75g of water.
 
You can dose that whole 30 at once but don't do any more than that for another 24 hours if you are planning to go higher than 8.5
 
Thanks for the suggestion. I just hit it with another 20 ml of Red Sea alk. I will test it in the morning and will let you all know how it’s going.
 
Yup np at all. I literally run the exact same tank setup so I'm familiar with the dosing. I have to dose about 17ml of alk a day to just to keep it steady at this point.
 
first it sounds like your tank is pretty stable which is good. There's a few things going on here..
First of all, every single time you go on vacation your tank is going to do better without you. Less hands in the tank. Less tinkering. Lower c02 in your home = higher PH = higher alk consumption.

secondly, I recently gave up on Hanna alk tests. I'm a control freak. Hanna themselves, claim an accuracy of plus or minus .3dkh or 05% of reading. I used to test my tank every night, this went on for over a year until eventually I noticed very very weird trends. The last 1/5 of the bottle is garbage. You're going to get nut readings using that last part of the bottle. Also I'd test two times back to back and get wildily different results
sometimes up to .8 dkh. Hanna would like to call this "testing error" but I think it's a Hanna error.
You sound a lot like me. I was looking for accuracy that I don't think yet exists in hobby grade test kits.
I switched over to salifert. It's a titration, there's less variables and I think it's more accurate and REPEATABLE. I test way less often and my tank looks great. I used to have a running count in my head between bottles of Hanna. I would make sure I finish a bottle and open a new one on the same night within minutes of each other. Last of a bottle would read 8.3, new bottle would read 7.5. So I would say "+.8"
every test out of the second bottle I would add .8 to the result. Then a new new bottle would be opened and the count would change. I drove myself mad with this Hanna card counting thing running in my head. Talk about taking stuff too far. And I learned this madness from a noteable YouTube personality with some successful tanks. Not worth it.

my advice is ditch the Hanna, get a salifert, buy some dosers, get some more experience under your belt until you can comfortably not take this all so seriously.
 
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Agreed with the above. Hanna while great (I still use them) I have saliferts as backups. Do get yourself a dosing unit and then just monitor it weekly it takes a lot off your plate and less to worry about.
 
As it turns out my Hannah checker went bad. I never could get a reading above 7.8 no matter how much I dosed my tank. So I ordered a new one on Amazon and my first test showed a reading of 8.0 and the old one showed 7.0
 

Hallowhead

NJRC Member
Jon,

It could have been the reagent you were using, try the old tester with the new reagent. I agree with the above though, always have a cheaper secondary test kit on standby for times like this. It is also possible your tank is starting to mature further and consume more alk.
 

amado

Dal
Staff member
Board of Directors
NJRC Member
Instead of dosing why not just do a large water change.
It will reset your tank. I like the Hanna i use it to check my trident.
I wouldn’t worry about small alk swings. 7dk - 11dk is fine especially for LPs and soft corals.

when you get a chance you should pick a doser.
 

MadReefer

Staff member
NJRC Member
Moderator
I feel your pain. ever since I switched to All for Reef powder and mix my ALK won't go above 7.1; liquid was at 8.2
Not sure if its me but mixed 3 batches or if the inhabitants just using more ALK.

Initially dosed 8ml daily
Today I bumped it to 15ml

This was a very gradual change over several weeks.
 
I feel your pain. ever since I switched to All for Reef powder and mix my ALK won't go above 7.1; liquid was at 8.2
Not sure if its me but mixed 3 batches or if the inhabitants just using more ALK.

Initially dosed 8ml daily
Today I bumped it to 15ml

This was a very gradual change over several weeks.

Powdered version of supplements tend to be less potent. I know for instance the RedSea Alk liquid is much stronger than if you mix the powder yourself.
 

MadReefer

Staff member
NJRC Member
Moderator
Glad to hear I am not going crazy. Well at least not yet.
Tested this morning and was 7.3. Added 20ml of solution along with dosing tested 2hrs later and dropped to 7.1.
I use a Hann Checker and thinking the battery is bad, even though supposed to be new as of 2 months ago.
Can the light be going bad?
 
So since you are suing All for Reef the one cavate to using it is that the alk in carbo calcium (formate) will not show up as alkalinity unless and until something metabolizes it and releases the alk back to the water.

So basically it won't show up as alkalinity as soon as you add it or even possibly an hour later unlike specific alk dosing like red sea which will instantly show a change.
 
Tested this morning and was 7.3. Added 20ml of solution along with dosing tested 2hrs later and dropped to 7.1.
I use a Hann Checker and thinking the battery is bad, even though supposed to be new as of 2 months ago.
Can the light be going bad?
Try to dose soda ash, afr it’s a bit hard to bring your alk up!!!
 
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