Low dKH

[MikeyZo]

I haven’t tested my tank in a while, everything seems status quo. But I decided to (I know I have chronically high PO4) to check PO4 and threw the gamut of tests in. My results were

Ammonia - .01
Nitrite - .03
Nitrate - 18.2
Phosphate - .78
PH -8.0
Magnesium - 1680
Calcium - 471
dKH -5.14

So I’m trying to bring the alk up without upsetting the system too much. Im using some TM All for Reef and ESV B-ionic. Obviously I’m going very slow, and I’m not using the ESV calcium dose yet, just the alk dose. But when i do dose it, it’s creating precipitate. Can I get a little help?

 

[UnnamedReef]

What types of test kits are you using? If API something more accurate should be used before making large changes

How old is the tank? If mature then Nitrite and Ammonia should be 0.

How's it stocked? Phosphate is really high but Nitrates are OK.

Have you checked your salinity? Low salinity could contribute to low alk

 

[exnisstech]

PO4 is high by many standards but I have a tank that runs higher than that as well as higher Nitrates and the tank does well with no nuisance algae.
I've used ESV 2 part for years and have no issues with presipitation (?) I manually dose by pouring it in front of a power head but dosing in the sump return chamber works also.
I run one tank with just ESV 2 part. I maintain alk in my SPS tank using AFR but I have used ESV to increase alk when needed like if I have a growth spurt then back to maintaining it with AFR.

 

[MikeyZo]

They’re all Hanna except the ph, that’s Red Sea. And I double checked the Hanna with the read sea alkalinity test kit. Got same reading

What types of test kits are you using? If API something more accurate should be used before making large changes

How old is the tank? If mature then Nitrite and Ammonia should be 0.

How's it stocked? Phosphate is really high but Nitrates are OK.

Have you checked your salinity? Low salinity could contribute to low alk

 

[MikeyZo]

PO4 is high by many standards but I have a tank that runs higher than that as well as higher Nitrates and the tank does well with no nuisance algae.
I've used ESV 2 part for years and have no issues with presipitation (?) I manually dose by pouring it in front of a power head but dosing in the sump return chamber works also.
I run one tank with just ESV 2 part. I maintain alk in my SPS tank using AFR but I have used ESV to increase alk when needed like if I have a growth spurt then back to maintaining it with AFR.

Yes, this was my thinking. Use AFR and just the ESV Alk for now. But when I poured the esv in, it was like snow. Maybe because it wasn’t near the mp10 or the return pump? Is it that finicky with flow?

And yeah, my tank has ran with high po4 from the get go. Leeching out of the old rock I used from my tank I broke down 15 years ago. but like I said, no issues other than color washing.

 

[exnisstech]

It does come out white very similar to coral snow but poured slowly in front of a power head has worked fine for me. If you have a sump you can also pour it into the return pump while it's running.

 

[MikeyZo]

It does come out white very similar to coral snow but poured slowly in front of a power head has worked fine for me. If you have a sump you can also pour it into the return pump while it's running.

Ok I’ll give it a try. If you have any other ideas or suggestions I’m all ears.

 

[MikeyZo]

What types of test kits are you using? If API something more accurate should be used before making large changes

How old is the tank? If mature then Nitrite and Ammonia should be 0.

How's it stocked? Phosphate is really high but Nitrates are OK.

Have you checked your salinity? Low salinity could contribute to low alk

Tank is over a year old, not overly stocked. And salinity is 34.2 (Hannah digital meter).

No room for increasing salinity.

I also use a salt that mixes at 8 dKH but 5 is just obviously

 

[UnnamedReef]

Interesting, do you see a change when you dose? I.E if you use a dosing calculator to dose a reasonable incremental amount and retest a few hours later, do you see that change?

 

[MikeyZo]

Interesting, do you see a change when you dose? I.E if you use a dosing calculator to dose a reasonable incremental amount and retest a few hours later, do you see that change?

I’ll try it tomorrow, I didn’t think to retest so soon.

 

[MikeyZo]

Interesting, do you see a change when you dose? I.E if you use a dosing calculator to dose a reasonable incremental amount and retest a few hours later, do you see that change?

I just added a dose of AFR and the ESV alk. I will test it again after lunch and report.

It does come out white very similar to coral snow but poured slowly in front of a power head has worked fine for me. If you have a sump you can also pour it into the return pump while it's running.

Amazing. I never thought it would matter that much. I did it slow right in front of the return and absolutely no precipitate! Thank you! Such a simple thing, never even thought of it.

 

[Randy Holmes-Farley]

I just added a dose of AFR and the ESV alk. I will test it again after lunch and report.


Amazing. I never thought it would matter that much. I did it slow right in front of the return and absolutely no precipitate! Thank you! Such a simple thing, never even thought of it.

Many alk supplements are very high in pH, including the alk part of B-ionic. When they first mix into tank water, some magesium hyroxide immediately precipitates. If you mix it in appropriately rapidly, the mangesium hydroxide redissolves as the pH around it drops back again.

If you let this high pH region sit for too long not mixed in, a slower and more problematic process takes over: precipitation of calcium carbonate. That material will not redissolve. That is one reason why adding all such supplements to a high flow area is recommended. The other is to avoid that high pH cloud from interacting with organisms before it mixes in.

 

[MikeyZo]

Thank you @Randy Holmes-Farley. That makes sense.

You make me wish I had paid more attention during organic chem and inorganic chem in college

 

[MikeyZo]

Interesting, do you see a change when you dose? I.E if you use a dosing calculator to dose a reasonable incremental amount and retest a few hours later, do you see that change?

Yup. It changed. Back up to 8.2 pH and 8.1 dKH. I’m going to back off the ESV and continue AFR and check it again in a couple days and see how it’s holding. Thanks all for the input.