Unexpected Alkalnity Usage

Nanoman71 · Aug 28, 2017

Hello everyone, I recently moved from a 14G biocube to a 25G lagoon tank from IM. I had always done weekly 50% water changes and not really checked much except for nitrates and phosphates (which were always high anyway.)

I bought the Hanna phosphate checker (fantastic tool by the way) and was astonished to see Phosphate levels of 2.0 ppm. I used 2 Seachem 100g phosguard packets. (each good for 50 gallons) and replaced them 3-4 times before I finally got levels down to .02. I left both the packets in there, thinking if 1 is good, 2 will be great (I know I know).

Anyway, my main question is I am having alkalinity drops of 30ppm/1.5 dkH per day (and that is with dosing kalwasser with my ATO @ full-dose of 2 TSP per gallon.

That sounds extremely high consumption from what I have read. My tank has a 2" sandbed, mainly zoas, a RTBA, and a Hammer - but not stonys or anything else. Probably not even 1/2 stocked yet.. (2 snowflake clowns and a cleaner shrimp)

Is it possible that by using "too much" phosguard would drop alkalinity levels so sharply? Any other ideas? I am also using (1) Chemi-Pure Elite 6.5 oz bag

R/O DI Water Source / 0 TDS
Temps - Consistent 78F
Nitrates 0
Phosphates .02
ph (8.4 when alklanity is right, 7.6-7.8 when alk is low)
Calcium (originally balanced by not recently checked)
Magnesium 1100

Red Sea Coral Pro Salt
(1) Ecotech MP10
2 Sicce return pumps
In-Tank Media Baskets
Tunze 9001 skimmer
Tunze ATO

Thanks in Advance!

Randy Holmes-Farley · Aug 28, 2017

2 KH per day is easily attained by coralline algae, so depending in what is in your tank, that might be some or most of it.

You may also have increased abiotic preciptiation of calcium carbonate substantially. That precipitation is slowed by a number of things, including organics and phosphate, and very heavy Phosguard use will drive both of those down and may have accelerated precipitation onto sand, rock, pumps, heaters, etc.

If that is it, the effect may decline as you stop replacing the Phosguard so fast.

What alkalinity level are you trying to maintain?

The magnesium, if accurate, also seems too low and bringing it up to appropriate levels will also reduce precipitation.

Scorpius · Aug 28, 2017

My guess is you have precipitation. My packed sps dominant 70 gal system uses only around 70ml each of Alk/Ca 2-part.

Nanoman71 · Aug 28, 2017

Thanks guys..

Don't have any visible coralline algae yet. (tank set up only 6 weeks)

My plan has been to maintain alkalinity somewhere around 9 dKH / 170ppm.

If I reduce the precipitation (removing phosphate and increasing mag) will that alk re-enter the water column?

Tautog · Aug 28, 2017

If your tank is only six weeks old, your still cycling. If there's no Coraline or corals in your tank, there's no reason to dose. WC at half your volume is too much per week. Wait at least a month before WC for now. Then only 25% for a water change once a month or every two weeks and no dosing until you need. Your WC at a correct salinity should be enough for now

Nanoman71 · Aug 28, 2017

Tautog, It is an "established tank" - just new glass. I used the sand and rock from a 3 year old tank to move over into this new glass. It never even really cycled 6 weeks ago when I made the transfer.My old tank had a lot of coralline, I didn't move any over on purpose.

I just started testing, so has been interesting to watch - and to try to understand what is happening. Something seems to be using the alkalinity, even if it is just precipitating.

LAstly, I USED to do heavy water changes (in the 14G tank) and never dosed anything.

I don't do heavy water changes with the new tank, so I am monitoring tank parameters ( which generates a lot of questions)

Randy Holmes-Farley · Aug 28, 2017

Nanoman71 said:
If I reduce the precipitation (removing phosphate and increasing mag) will that alk re-enter the water column?

nope, but you can stop more from disappearing that way.

Nanoman71 · Aug 28, 2017

Randy Holmes-Farley said:
nope, but you can stop more from disappearing that way.

Thank you Sir!

GoPitt88 · Aug 28, 2017

I'm basically having the same issue. Losing about 1.2 dKH per day. Just started using Kalkwasser for the first time, and I'm up to 1.5 teaspoons per gallon in my ATO water. We'll see how that goes. I fill two bags with GFO in my canister filter....not sure that's why I'm losing so much dKH? Maybe I'll start cutting back on that as well.

Nanoman71 · Aug 28, 2017

GoPitt88 said:
I'm basically having the same issue. Keep me posted what you learn

Have you checked your magnesium GoPitt88?

GoPitt88 · Aug 29, 2017

Nanoman71 said:
Have you checked your magnesium GoPitt88?

Yes. A few days ago, it was high, off the chart. 1500+. I do weekly 10% water changes using Reef Crystals.

Randy Holmes-Farley · Aug 29, 2017

FWIW, some ongoing precipitation is not necessarily a bad thing. It likely takes out some phosphate with it.

Brew12 · Aug 29, 2017

Nanoman71 said:
Tautog, It is an "established tank" - just new glass. I used the sand and rock from a 3 year old tank to move over into this new glass. It never even really cycled 6 weeks ago when I made the transfer.My old tank had a lot of coralline, I didn't move any over on purpose.

I just started testing, so has been interesting to watch - and to try to understand what is happening. Something seems to be using the alkalinity, even if it is just precipitating.

LAstly, I USED to do heavy water changes (in the 14G tank) and never dosed anything.

I don't do heavy water changes with the new tank, so I am monitoring tank parameters ( which generates a lot of questions)

Did you add any new sand or live rock when you moved the system?

Nanoman71 · Aug 29, 2017

I did add new rock, (50% is new) although it was already cured/wet. I also added 20# of new sand. I assumed the new rock was leaching phosphates, which is why I used so much phosguard

Nanoman71 · Aug 30, 2017

Randy and Team, Hopefully yall will stick with me until I get this sorted out...

2 days ago, I removed the phosguard(s) as discuused in this thread, and yesterday did a 50% water change to reset things.

I used Coral Pro Salt (see parms below) My salinity is 1.023. I checked my Alk an hour after the massive water change yesterday, and got 11.4 dKH. Today, 24 hours later and my Alk is 8.7dKH. So my daily consumption/precipitation of ALK was of 2.7 dKH.

I don't have a MG test kit yet, but believe that my levels are "high enough" to prevent precipitation based on the water change. Considering I was 1100 mg/l before (had LFS test) and the new mix is ~1300, I assume I am ~1200 mg/l.

My ATO hasn't run all that much, so the 2 tsp/g kalwasser may not have had an impact.

My new pH meter came in though, and Immediately after the water change yesterday I was at 8.3, and today it is still at 8.3

Any ideas on how to get the tank stabilized so the ALK doesn't dissapear

2 Part kit should be here soon, but wondering what I'm even going to do with it at this point if I had it. :-(

Tautog · Aug 30, 2017

Wow, that's a large change in Alkalinity in one day, especially for a small tank, must be precipitating out. I use IO Crystals, and at mix my Alkalinity is 12.4 dKH, then after the WC the next day I'm at 8.4 dKH. I usually wait and let my Alkalinity drop to 7.0-7.5 before the WC, thus allowing things to balance out by the following day. I'm dosing 100 ml/ day of 2- part, and now need to add more due to coral growth. My system is 200 gal total with 60+ corals, with very little precipitation.
I can't believe weekly WC's of 20% would be enough without dosing 2- part.
Just trying to help, but I had these same issues until I finally figured things out. One suggestion would be to stop everything for 3 days, then test DT, test WC prior to replacing, wait a day, then test DT to see where your at. Test Alkalinity everyday at same time, very important, and see, log everything you do.
On paper, things look better, and may help more. Don't worry I'm trying help, but learn something too. My salinity is at 1.026 - 1.024

Randy Holmes-Farley · Aug 31, 2017

The demand for alk will decline as the alk declines.

What is your desired target alk level??

Nanoman71 · Aug 31, 2017

@Randy Holmes-Farley, My target is wherever the tank wants to settle in; hopefully 8.5 -9.

Today's reading is 8.1dKH and ph is 8.2. To summarize, the first 24 hour ALK drop 2.7dKH, this past 24 hours 0.6 dKH.

I will continue to monitor, and appreciate the ongoing support!

Tautog · Aug 31, 2017

Nanoman71 said:
@Randy Holmes-Farley, My target is wherever the tank wants to settle in; hopefully 8.5 -9.

Today's reading is 8.1dKH and ph is 8.2. To summarize, the first 24 hour ALK drop 2.7dKH, this past 24 hours 0.6 dKH.

I will continue to monitor, and appreciate the ongoing support!

That 0.6 dKH is very good and about normal, now go to the BRS calculator based on your water volume and you'll find out how much your need to add everyday to stabilize

Nanoman71 · Sep 11, 2017

I wanted to follow up and say THANK YOU to everyone; I finally think I have tackled this..

I'll share my testing and process for anyone who might be interested.

Let me first say, I cannot recommend Hanna checkers enough. I have the Alk and Ca, and Phosphates checkers. HINT - Order extra reagent for testing, as you will go through a bunch at first..

I have decided to try to maintain Alk in the 150-160ppm range (8.4-9.0 dKH,) and keep Ca near 420-425ppm.

The first thing I did was raise Mg to 1400mg or so, to make sure I removed any option of low Mg causing precipitation. I also lowered my Kalwasser solution to 1sp/gallon vs 2. My ph was getting up to 8.5 + during mid-day; but has since moved closer to 8.2-8.35. (At night, it drops to 8.05 - 8.15)

I have measured Alk 3X a day for the past 3 days. I have noted what I added and when, I have tightened up my ranges considerably. In hindsight, I probably changed too much too fast, and would extend this out, but with the bad weather, and my business schedule, I went at it pretty quickly. If any one is struggling - if you do this 3X a day for 3 days, you CAN dial it all in.

On Friday, I started the day at 111ppm of Alk,; I added 33ml of 2 part over the course of 12 hours to end up at 133 that night (which implies a LOT of consumption considering 33ml=54ppm) I didn't lose much Alk overnight, starting with 131ppm, and added another 33ml of 2 part over the course of the day, ending the day with 160ppm Saturday night. Didn't lose much again Saturday night, starting at 155pm, and only added 13ml 2 part over the course of the day) and still ended the night at 154G. So I am not sure if Alk consumption has dropped significantly, OR if things are just getting balanced and minimal precipitation. I checked Ca for the first time Sunday, should have done it sooner, and it was seriously low (380) so I added Ca in equal daily doses to get it to 420 today.

One thing that is interesting; I only added 13ml of 2-part Sunday and went to bed with 154ppm.. Today (Monday AM) it looked like it had increased slightly (to 157ppm.) Probably just a test anomaly, and I will test again tonight, expecting it to settle in, somewhere in the 10-15ml/day consumption.

Future water changes; have to tighten it up (otherwise everything gets out of whack again and automated dosing may not work) I have always been a little sloppy with using cups per gallon for salt, so I am now using some digital scales I had to measure 37 grams/liter. Also, once my dosers come in, I might actually get away from Kalwasser, to extend reliability of the ATO, and also provide more measured delivery. (Every power blips causes Kalwasser to run for a a little bit - harder to manage.)

SO now after getting everything exactly where I want it (or at least understand what is happening,) Irma is probably going to knock out my power and screw it all up...