Alk rising without dosing?

[wtusa1783]

I have a new tank and was using instant ocean reef crystals and my alk and calcium were high. I got some new salt with lower parameters and have been doing a water change once or twice a week now. I have never dosed alk but it seems to be rising the next day after a water change. Here is my chart from my trident and it shows how I do a water change to drop my alk but it slowly rises again. What’s the issue?

 

[Radicalrob1982]

Not sure what's going on but sometimes if you lower nitrates your alk will rise. Are you heavily stocked or feed a lot? Nitrates kinda acts like an acid that lowers alk

 

[wtusa1783]

Not sure what's going on but sometimes if you lower nitrates your alk will rise. Are you heavily stocked or feed a lot? Nitrates kinda acts like an acid that lowers alk

I have 5 fish in a 120 and feed once a day so I wouldn’t say it’s heavily stocked. Should I try feeding heavier then?

 

[Radicalrob1982]

Well if new water has alk it will raise your alk. And also if your lower nitrates your alk will rise. So doing 2 water changes a week will surely raise your alk. Even tho the new salt has lower alk it still adds to the alk that it's in your tank because it has alk. Best to let it slowly wind down or dose alk as it depletes. As long as your nitrates stay in acceptable levels there's no need to do a water change. Keep an eye on alk and mag/calc and dose accordingly.

For example my nitrates take forever to go above 5 ppm. So by keeping an eye on it I need to do a water change every 3 to 4 weeks to keep them there in that area. But my alk goes down roughly 0.2 meq/l per day. So I dose daily to keep it at 7.5 for stability. My calc and mag go down slow. So I test those once a week and dose accordingly.

 

[Radicalrob1982]

I have 5 fish in a 120 and feed once a day so I wouldn’t say it’s heavily stocked. Should I try feeding heavier then?

Yeah so just to clarify. If your alk is say 10. But ur new saltwater is 8. It will still raise your alk because you have new/more alkalinity coming in.

 

[wtusa1783]

Yeah so just to clarify. If your alk is say 10. But ur new saltwater is 8. It will still raise your alk because you have new/more alkalinity coming in.

Why does it go down when I do a water change then? It’s not going up until a day later

 

[Radicalrob1982]

Something weird is happening because a water change should boost your alk. Not take it away. The only thing I can guess is that the new water hasn't saturated yet. Meaning it hasn't chemically bonded all together. Then the next day it has and that's why you see the rise in alk. I've never tested my water right after a water change. I always test it the next day and see that my levels have rose. Hence the point of doing a water change and to rid excess nutrients.

There's a person on here named Randy holmes farly I believe. And he is also from what I hear a Reef chemist. I believe he would know exactly what's happening in your tank. I would suggest trying to get in touch with him

 

[120reefkeeper]

The answer to the op’s question could very well be answered within this thread . Read what Randy says here about the relationship between nitrate and alkalinity.

Need to raise alkalinity

Hey @Randy Holmes-Farley, First off, thank you for all that you do. You're greatly appreciated by everyone here. Without you, a lot of people wouldn't be able to make it in this hobby. Now that I've kissed the ring on your finger, time for advice. I'm wanting to raise my alkalinity from 6.8...

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