low alk after water change

[Atrawick]

I have a 36g FOWLR. Haven't done a water change in 6 months. I know i should be ashamed. Trying to get the tank back to a stable state. Water change done yesterday.
Test done today
ph 8.2
alk 5.4
cal 490
mag 1500
phos kit oredered
I have bh50 skimmer and just added a AC70 with charcoal and Phosguard. Been battling brown hair algae.

how do I raise the Alk?

 

[Mastiffsrule]

Don’t be ashamed. I have done the same. What salt are you using? Your calcium and mag seem pretty high for not changing water unless you are dosing.

I would not be super concered about low alk w fowlr but if it gets to low it could start affecting the rock and substrate. I would check again tomorrow if still low you can use a buffer. Seachem has reef builder that raises alk, but need to be careful. I would have recommend kalk, but your calcium is already high.

Edit, now that I think about it you may be able to use baking soda or something like that. Do not try it until someone else chimes in on how to use it. I have never done it.

 

[Mastiffsrule]

Plus, did I say welcome? If not, welcome.

 

[Atrawick]

I used my old leftover salt. No dosing. Trying to get it ready for a reef tank.

 

[scriptmonkey]

I have a 36g FOWLR. Haven't done a water change in 6 months. I know i should be ashamed. Trying to get the tank back to a stable state. Water change done yesterday.
Test done today
ph 8.2
alk 5.4
cal 490
mag 1500
phos kit oredered
I have bh50 skimmer and just added a AC70 with charcoal and Phosguard. Been battling brown hair algae.

how do I raise the Alk?

Dont be ashamed mine was 12 months so I was in same boat. My Alk was at 4.035 dkh. I did 20% water change then manually dosing Red Sea Foundation part B back up to 7.9 and everything seems to be looking better. Coralline algae is taking off again. It seemed to also straight out my PH issues as well.

 

[lapin]

I used my old leftover salt.

Like old moonshine, it has lost its bite

 

[Atrawick]

After I used my old salt. I saw the thread on using old salt! Could I do a couple of WC to bring it up? With new salt of course!

 

[SeaDweller]

You can use baking soda. Use this site to help you calculate numbers.

http://reef.diesyst.com/chemcalc/chemcalc.html

 

[Atrawick]

Just regular Armor Hammer baking soda?

 

[SeaDweller]

Just regular Armor Hammer baking soda?

Yep. That’s what I use.

 

[Sam Dean]

If you overdose calcium, i believe it will drive down your alk numbers. I would dose with baking soda to stabilize and then ensure you are using a two part or kalkwasser dosing regiment.

 

[Atrawick]

If you overdose calcium, i believe it will drive down your alk numbers. I would dose with baking soda to stabilize and then ensure you are using a two part or kalkwasser dosing regiment.

I don't dose anything.The tank has 2 clowns and live rock. Just trying to fix my neglect.

 

[SeaDweller]

I don't dose anything.The tank has 2 clowns and live rock. Just trying to fix my neglect.

How big is the tank? Just dose the baking soda and watch the parameters.

 

[Atrawick]

36g

 

[Skydvr]

I heard something about alkalinity actually being important for fish growth, so even in FOWLER systems it is something to keep an eye on. I’m sure it doesn’t need to be as high as an SPS tank, but I don’t think your numbers are too far off. Alkalinity also helps stabilize pH.

Dosing for alkalinity will have a very strong affect on pH. It is typically not recommended to raise alkalinitly more than 0.5-1 dKH per day, ideally not dosing that all at once due to the increase in pH. There is a relationship between calcium and alkalinity, which the calculator in that link calls out. Magnesium also has an affect on calcium and alkalinity, but you are definately above the levels where that would be a concern. I am unaware of issues with elevated magnesium.

What salt are you using?
What is your salinity?

I ran some tests a while back and running tests on the same water at 34ppt and 35ppt changed calcium by 12ppm, magnesium by 35ppm, and alkalinity by 0.2dKH. If your salt bucket hasn’t stratified, skewing your numbers, it is possible that your salinity is high.