why does alkalinity keep dropping in newly set up 25g reef ?

[acropora4u]

Tank has been running about 3 weeks , started with real reef rock and Arag-Alive Special Grade Reef Sand. I used IO salt and ro/di water at a specific gravity of 1.026..

alk was 9.5 dkh when started and dropped to 5.2 within 1 week... i also add microbater7 at 5mls daily and adding 1 tsp of sodium bicarbonate a day now to bring alk back up to 7.5 dkh...why does the alk drop so much per day? i use hanna alk checker for results

also, this tank has zero corals or fish during cycle.

can anyone advise on this constant alkalinity drop?

 

[_Jake_Simek_]

That is an insane amount in one week with no coral. are you sure your testing is accurate? Hannas do a great job in my experience but it could be as simple as a dirty vile to screw them up.

 

[acropora4u]

That is an insane amount in one week with no coral. are you sure your testing is accurate? Hannas do a great job in my experience but it could be as simple as a dirty vile to screw them up.

its accurate...even used new reagent and new vials...same result as older vials and regent

 

[_Jake_Simek_]

its accurate...even used new reagent and new vials...same result as older vials and regent

that's crazy, you would normally only see that drop in a heavily stocked tank. Are you dosing any calcium?

 

[bushdoc]

Tank has been running about 3 weeks , started with real reef rock and Arag-Alive Special Grade Reef Sand. I used IO salt and ro/di water at a specific gravity of 1.026..

alk was 9.5 dkh when started and dropped to 5.2 within 1 week... i also add microbater7 at 5mls daily and adding 1 tsp of sodium bicarbonate a day now to bring alk back up to 7.5 dkh...why does the alk drop so much per day? i use hanna alk checker for results

also, this tank has zero corals or fish during cycle.

can anyone advise on this constant alkalinity drop?

I guess you are adding ammonia to your tank? It gets converted to nitrates and each molecule of ammonia converted to nitrate is producing one H+ ion, thus decreasing alkalinity. Looks to me like your cycle is working fine, just correct dKH with sodium bicarbonate.

 

[bud_rick]

Relationship between nitrate and alk

 

[bud_rick]

I guess you are adding ammonia to your tank? It gets converted to nitrates and each molecule of ammonia converted to nitrate is producing one H+ ion, thus decreasing alkalinity. Looks to me like your cycle is working fine, just correct dKH with sodium bicarbonate.

Disregard this reply. I was going to throw a tip in there regarding soda ash then realized he’s using bicarbonate.

 

[_Jake_Simek_]

I guess you are adding ammonia to your tank? It gets converted to nitrates and each molecule of ammonia converted to nitrate is producing one H+ ion, thus decreasing alkalinity. Looks to me like your cycle is working fine, just correct dKH with sodium bicarbonate.

ya learn something new everyday! that's actually really cool.

 

[marky]

I just finished the fishless cycle on my tank and I saw a similar drop in dKH, though from the mid 8's to the mid 6's. In fact when I dosed some soda ash to increase dKH, the next day all my nitrites were gone. Maybe that was just coincidence, but I think @bushdoc has the science right.

 

[acropora4u]

I guess you are adding ammonia to your tank? It gets converted to nitrates and each molecule of ammonia converted to nitrate is producing one H+ ion, thus decreasing alkalinity. Looks to me like your cycle is working fine, just correct dKH with sodium bicarbonate.

negative...only microbater7 is being added daily...no ammonia

 

[acropora4u]

that's crazy, you would normally only see that drop in a heavily stocked tank. Are you dosing any calcium?

only microbacter7 is being added , nothing else.

 

[bud_rick]

only microbacter7 is being added , nothing else.

What did your nitrates read after the tank was fully cycled? The Alk declines as the ammonia and nitrites are converted to nitrates.

 

[acropora4u]

API test ammonia is 0.
Salifert nitrite is .5
Salifert nitrate is 50

 

[bud_rick]

API test ammonia is 0.
Salifert nitrite is .5
Salifert nitrate is 50

If you read that article I linked in my reply above Randy Holmes-Farley explains how for each 50ppm of nitrate that is produced the alk will go down 2.3 dkh.

 

[acropora4u]

If you read that article I linked in my reply above Randy Holmes-Farley explains how for each 50ppm of nitrate that is produced the alk will go down 2.3 dkh.

Guess I’ll keep feed sodium bicarbonate daily

 

[acropora4u]

It’s looking good though

 

[bushdoc]

negative...only microbater7 is being added daily...no ammonia

But you are cycling the tank, so if no fish, no ammonia then it must be ghost feeding or dead shrimp? You must be adding some source of ammonia to the tank to cycle it.Even if it is just live rock, it must’ve had some growth which died and is decomposing.

 

[acropora4u]

Ohh. I started with redsea starter kit reef mature

 

[john90009]

In a newly established tank there’s a lot of binding going on wether it’s to the substrate or the rocks- in the beggining of my tank I was doing a lot to get it to budge up , it seems once it was saturated then it started to move but make sure once it starts to move to tune down the dosing. Same thing with nitrates and phosphates for me .

 

[HomebroodExotics]

During the start of a cycle there is a lot of biological processes going on that you cant see. This will all consume alk. It will also consume a lot more magnesium in the beginning as well from my experience. Looks great, enjoy.