Alkalinity Drops (9.0 to 6/7 overnight)

[Leon.NYC]

Hey all,

Can use some advise here. My tank is a Waterbox 230.6 & I'm having issues maintaining my dKH, even with Kalk dosing (3,000ml per day). I've been dosing roughly 250ml BRS Alk solution (soda ash) every 12 hours or so. Generally, I'll add soda ash around 5pm when i finish work & top off Alk to keep at 9 dKH. I'll then test again the following day at noon and my Alk would be very low. Sometimes its high 6's, earlier today when i tested at noon, it was 7.3, although I changed my doser to constantly dose Kalk (3.5ml/minute). I don't see the small corals i have up taking all this Alk. Prior to dosing the Kalk 24/7, dKH would drop to 6.7 (roughly).

Note: The tank is fairly new. If you take a look at my build, it was setup in early Sept., although I did use some bio media from my previous tank that's been operating for roughly 3-years. I also added a bunch of media to a bucket & let it sit for roughly 2 1/2 months while performing ghost feedings every few days & adding new bacteria (Fritz Turbostart 900 & PNSB).

@Randy Holmes-Farley maybe you can provide some insight & next steps?

Note: Today i also noticed towards the back of the tank, there's a large chunk of sand that's hardened like a brick.

I am thinking of switching to All for Reef as my pH remains high.

• Calcium: 420-450
• Alk: 9.0 (ideal)
• Mag: 1450
• PH: 8.4-8.7 (currently swings with dosing soda ash)
• Nitrates: <2 (currently fighting to raise)
• Phosphates: .02

Corals include;

• 3 Torch frags
• 5 hammer frags
• 1 Lobo
• 1 Green Slimer
• 1 Jades Dragon birdsnest
• 1 Favites
• 1 Favia

Thanks in advance!

 

[Jorgehiram]

Can you get another test from a friend or local shop? I believe this is a test error. I, too, have a 230.6, just a year old, and have more corals. I also used some live rocks from an established old system, but I only use 35 ML a day of AFR and water changes to keep up. No two systems are the same, but these are similar, and dosing alk plus kalk, that's a considerable amount. Take your test and test a fresh batch of saltwater, then compare it with the salt specifications to see if there are any errors.

 

[buruskeee]

Please let is know how you are testing.

 

[ScottF]

Are you dosing calcium chloride into the same area of the tank/sump at the same time as the soda ash solution? Does the area where you are adding the soda ash solution have a lot of flow? Are you sure that your mag is 1450?

It sounds like it's just precipitating out. Especially with that brick of sand.

 

[Leon.NYC]

Thanks all, I’m using the Red Sea pro test kit along with salifert.
After doing some digging and looking Into some of the comments with similar issues, it seems as though I’m precipitating out. I’m going to give it till Monday to allow it to stop then dose alk to get it back up slowly over the course of a few days.

 

[slythy]

Thanks all, I’m using the Red Sea pro test kit along with salifert.
After doing some digging and looking Into some of the comments with similar issues, it seems as though I’m precipitating out. I’m going to give it till Monday to allow it to stop then dose alk to get it back up slowly over the course of a few days.

You have to be precipitating it all out. I have a 280g sps dominate tank with a frag system and I do 1 gallon of kalk and 120ml of 2 part a day.

Where are you dosing? Into the return pump? Hows it spread out?

 

[Leon.NYC]

You have to be precipitating it all out. I have a 280g sps dominate tank with a frag system and I do 1 gallon of kalk and 120ml of 2 part a day.

Where are you dosing? Into the return pump? Hows it spread out?

Hi @slythy, I was dosing it into the skimmer chamber, then recently moved it to the return pump chamber. I'm now thinking when i do restart, I'll add it to the overflow drain instead. I noticed that after i stopped dosing last night, the pH dropped from 8.7 to 8.37 (currently). Is it safe to give it till Monday before i resume bringing back up Alk slowly?

 

[ScottF]

Are you using a dosing pump or just dumping 250ml of soda ash solution in all at once? If you are just dumping that much in at once, you really need to dump it into extremely high flow and you want to pour very slowly or the sodium carbonate will combine with the calcium in the water and precipitate out.

 

[Leon.NYC]

Are you using a dosing pump or just dumping 250ml of soda ash solution in all at once? If you are just dumping that much in at once, you really need to dump it into extremely high flow and you want to pour very slowly or the sodium carbonate will combine with the calcium in the water and precipitate out.

Yes, I was using the Hydros Sole dosing pump for the Kalk.. For the soda ash I was dosing by hand (which i now stopped).

 

[slythy]

I would dose directly into your return pump chamber. High flow and quick distribution. Into the drain or skimmer i dont feel does as well ( on zero scientic backing, just a feeling)

 

[Leon.NYC]

I would dose directly into your return pump chamber. High flow and quick distribution. Into the drain or skimmer i dont feel does as well ( on zero scientic backing, just a feeling)

Got it, thanks. Do you suppose sunday evening is long enough or too long? As noted before, the pH has dropped from 8.7 to hovering at 8.4. I'll assume itll drop a bit more overnight.

Note: I'm tracking pH via Hannah probe/pen & Hydros pH probe.

 

[ScottF]

I personally try to keep my pH between 8.3 and 8.5, but I wouldn't be too worried at 8.7. There are people out there that like to push the limits that run a higher pH than that.

If I were you, I'd just try to stabilize things. Maybe try adding less sodium carbonate more slowly.