My dkh keeps dropping back to 6

[AJA45]

I have had my tank cycling for 5 weeks with no livestock and I keep dosing to make my dkh go up to 7 or 8 but after 2 days it falls back to 6, why is this

 

[Garf]

I have had my tank cycling for 5 weeks with no livestock and I keep dosing to make my dkh go up to 7 or 8 but after 2 days it falls back to 6, why is this

Is the sand going hard?

 

[AJA45]

I have had my tank cycling for 5 weeks with no livestock and I keep dosing to make my dkh go up to 7 or 8 but after 2 days it falls back to 6, why is this

Is the sand going hard?

Yes, there is like a crust forming kind of forming on the top layer

 

[Randy Holmes-Farley Verified Community Expert]

Yes, there is like a crust forming kind of forming on the top layer

That’s a sign of precipitation. I’d stop dosing for a while.

What product were you adding?

 

[AJA45]

Yes, there is like a crust forming kind of forming on the top layer

That’s a sign of precipitation. I’d stop dosing for a while.

What product were you adding?

I was using reef fusion 2

 

[Randy Holmes-Farley Verified Community Expert]

Switching to a lower pH alk supplement can help. Baking soda is a good choice.

Stop dosing for a bit, then restart keeping the alk and pH on the low side.

 

[AJA45]

How long should I wait to start dosing again

 

[Randy Holmes-Farley Verified Community Expert]

This is my generic recommendation for excessive precipitation issues (such as hardening sand):


1. Stop all efforts to boost pH.
2. Stop dosing alk for a bit and let it decline.
3. Reduce pH by switching to a low pH alk mix like sodium bicarbonate, or a calcium organic such as Tropic Marin All for Reef.
4. Ensure magnesium is normal to high.
5. Keep organics and phosphate on the high side.

After a few days of not dosing alk, restart slowly, adding additives to a very high flow area so it mixes in fast.

 

[rishma]

This is my generic recommendation for excessive precipitation issues (such as hardening sand):


1. Stop all efforts to boost pH.
2. Stop dosing alk for a bit and let it decline.
3. Reduce pH by switching to a low pH alk mix like sodium bicarbonate, or a calcium organic such as Tropic Marin All for Reef.
4. Ensure magnesium is normal to high.
5. Keep organics and phosphate on the high side.

After a few days of not dosing alk, restart slowly, adding additives to a very high flow area so it mixes in fast.

Assuring magnesium is normal to high is a bit tricky. Any advice Randy? Just spitballing here, off the top of my head…

If I owned a magnesium kit, I’d do the following:
- mix fresh saltwater
- test it twice back-to-back. What ever number you get, assume that is “normal”
- test the tank
-dose magnesium to tank to exceed the freshly mixed saltwater number.

If I didn’t own a magnesium test kit, I’d dose enough magnesium to raise tank by 50 ppm.

 

[Randy Holmes-Farley Verified Community Expert]

Assuring magnesium is normal to high is a bit tricky. Any advice Randy? Just spitballing here, off the top of my head…

If I owned a magnesium kit, I’d do the following:
- mix fresh saltwater
- test it twice back-to-back. What ever number you get, assume that is “normal”
- test the tank
-dose magnesium to tank to exceed the freshly mixed saltwater number.

If I didn’t own a magnesium test kit, I’d dose enough magnesium to raise tank by 50 ppm.

I’d ignore magnesium levels if you do not have a recent icp.