Can Not Get Alkalinity and Calcium Right

[JCas06]

Hello all,

I have had my 72 gallon bowfront mixed reef tank for around 5 years now. I lived in Boca Raton FL for the first 2.5 years and would use natural sea water from off the coast. Corals always looked great, water tests by LFS were always good on params. The only things I would ever add to the tank were some seachem buffer, and calcium carbonator (which I have read is useless and do not use anymore).

Anyways I moved a few hours north 2.5 years ago now where the water off the coast is not as crystal clear as South Florida so I purchased a RODI and Coralife salt mix and started making my own water. After a while my corals were not looking so good and making the saltwater was a pain because of my well water having high tds and CO2 levels. So I started using NSW from the ocean again which made a slight improvement. Fast forward to a few months ago and I really started testing my parameters because I wanted a thriving tank again. I found my Ph is always low at 7.8 . Calcium was super low. Alkalinity was low. Magnesium may have been low or decent I do not remember.

So I started dosing limewater and continued testing and it did not seem to have any great affect. Ph always at 7.8 and still really hard to keep Alk and Cal levels up. I then bought 2 part (Recipe 1 with soda ash) and Magnesium from BRS and would manually dose that which would bring my Alk up to 9 dkh, Cal to 420, and Mag to 1450-1500. But the next day I would test and Alk would be down to 6 or 7 dkh again, Calcium 360 - 400 and Mag never dipping much below 1500 even though I would not add more. I also noticed dust on my magnetic frag rack and on my gyre pump. I initially started at 50 ml each Alk and Cal, then up to 75 ml, then 100 ml, then 150 ml per day each. But no matter what I dosed the next day the numbers would be low again. Especially Alkalinity, always retreating back to 6 or 7 dkh with Ph of 7.8 like clockwork. I never got a snow storm but I always would be blowing off dust from frag rack and pump. Then I noticed the glass on my tank was building a white haze. It was hard to scrape off and felt chalky. I stopped dosing two part for a few days and went back to limewater. Params on limewater still low so started 50 ml of two part again and glass started to haze up again. So I stopped and now I am only doing limewater again with no idea how to move forward. Forgot to mention a few weeks ago I went back to Coralife salt mix made with RODI on city water. Did a 50% water change on 11/24/17 and tested before the water change, the fresh salt mix, and after the water change:

Before Water Change: Ph - 7.8 Alk - 6 dkh Cal - 400 Mag - 1500
Salt Mix: Ph - 7.8 (after gassing it, it was 12 at first) Alk - 11 dkh Cal - 400 Mag - 1200
After 50% water Change: Ph - 7.8 Alk - 9 dkh Cal - 400 Mag - 1450

The next day I tested again: Ph - 7.8 Alk - 7 Cal - 400 Mag - 1470

I have been using API test kits since starting in this hobby for everything except Magnesium (Salifert). Today 11/30/17 my all new Salifert test kits came in and I tested with both the old API kits and then with the new Salifert Kits for Ph, Alk, Cal, and Magnesium.

Old API Test Kits: Ph - 7.8 Alk - 6 dkh Cal - 390 Mag - 1365 (Salifert)

New Salifert Test Kits: Ph - 8.0 Alk - 5.1 dkh Cal - 410 Mag - 1440 test #1 and 1500 test #2

I still see dust on items in the tank. Do not know how to fix this. I ordered a bubble magus dosing unit so I will not have to manually dose anymore when that comes. I have tried adding the 2 part 5 minutes apart from eachother, 30 minutes, and hours apart. I still got the chalky haze.
Tank is pretty well stocked with coral, will include pictures. Only have 1 clownfish.

Pictures are of hazy glass, dust on sand, test results

 

[Randy Holmes-Farley]

First let's dispense with pH. You cannot easily control it by dosing. It is likely being driven down by elevated CO2 in your home air.

Second, it is not at all surprising that alk would drop 2 dKH per day.

I can understand the concern about precipitation, and it is not always easy to stop once it starts as each little crystal acts as a seed for more precipitation.

To reduce it, try targeting 7 dKH and not higher. The lower the alk the less precipitation there will be, and 7 dKH is a fine value. If it drop to 6.5 dKH overnight, dose back to 7 or maybe 7.25 dKH the next day.

Dose to a high flow are away from corals.

 

[Alfrareef]

@Randy Holmes-Farley how to stop Alk precipitation?

 

[Randy Holmes-Farley]

@Randy Holmes-Farley how to stop Alk precipitation?

I suggested how the OP should proceed (IMO), but in general...

1. Take a break from dosing to allow the existing and growing calcium carbonate surfaces to "cool off". That is, get coated with other stuff that reduces precipitation.

2. Keep pH on the low end. pH 7.8 compared to pH 8.2 is a massive effect, reducing the likelihood of precipitation.

3. Keep alkalinity and calcium at the low end of OK (say, 6 dKH and 350-400 ppm calcium).

4. Keep magnesium, phosphate, and organics high as all of these get onto growing calcium carbonate surfaces, preventing more precipitation.

 

[Alfrareef]

Understood Thanks!
Sorry to the Opp for thread hijack

 

[JCas06]

First let's dispense with pH. You cannot easily control it by dosing. It is likely being driven down by elevated CO2 in your home air.

Second, it is not at all surprising that alk would drop 2 dKH per day.

I can understand the concern about precipitation, and it is not always easy to stop once it starts as each little crystal acts as a seed for more precipitation.

To reduce it, try targeting 7 dKH and not higher. The lower the alk the less precipitation there will be, and 7 dKH is a fine value. If it drop to 6.5 dKH overnight, dose back to 7 or maybe 7.25 dKH the next day.

Dose to a high flow are away from corals.

Thank you for your insight. I assume I dose equal parts of alkalinity and calcium still? How long do I keep it low until I try to get the levels up higher again?

 

[Randy Holmes-Farley]

Thank you for your insight. I assume I dose equal parts of alkalinity and calcium still? How long do I keep it low until I try to get the levels up higher again?

Keep what low? I'd boost calcium alone now.

Then some hours or a day later, boost equal parts based on your alk target.

 

[JCas06]

You mentioned targeting 7 dkh for alkalinity which is on the low end of recommended range so that's what I was referring to. How long do I keep alkalinity targeted at 7 dkh before I try and take it higher.

You mentioned you would boost calcium alone now. Did you mean to say alkalinity?

Just tested my water:
Ph - 7.9 or 8.0
Alkalinity - 4.5 dkh
Calcium - 410
Magnesium- 1440

 

[Randy Holmes-Farley]

You mentioned targeting 7 dkh for alkalinity which is on the low end of recommended range so that's what I was referring to. How long do I keep alkalinity targeted at 7 dkh before I try and take it higher.

You mentioned you would boost calcium alone now. Did you mean to say alkalinity?

Just tested my water:
Ph - 7.9 or 8.0
Alkalinity - 4.5 dkh
Calcium - 410
Magnesium- 1440

Oops, sorry. I confused two threads with very similar titles.

Use normal baking soda (not sodium carbonate) to boost the alk back to about 7 or 7.5 dKH and check again after 24 h. Keep doing that for a few days and see if the drop after dosing begins to decline.

 

[BlakeP]

Following. But have a quick question. I’ve got the same problem. If alkalinity is boosted back to 7 or 7.5, does calcium need to be dosed to keep the balance?