I hate water chemistry

[Bernardhny]

Awhile back I started dosing and had major problems. I decided to stop chasing numbers. Now I am ready to try again. Prior to my weekly water change I ran the numbers:

PH 7.82
Salinity: 1.026
Phosphate: .03
Calcium: 430
Alk: 5.04 dkh (90ppm)
Magnesium 1280

Of course the alk being so low is a big problem.

I did a 10g water change.

Post 1hr change I measured the water again:

PH 8.02
Salinity: 1.026
Phosphate: .03
Calcium: 430
Alk: 6.1 (110 ppm)
Magnesium 1350

I went to the BRS Alk calculator and it said to raise the Alk I need to add 3.5 ounces of my Alk mix. Of course I don't want to raise it that fast so I added 1 ounce tonight and will test tomorrow. My goal is to get the levels to:

Calcium 450
Alk 8.5
Mag 1350

Once I get to those levels I will measure the daily drop and counter with my dosers.

Anyone think my methods are off?

 

[Randy Holmes-Farley]

That method sounds fine, but you may need to boost alk faster to get there. The demand might increase as you add alkalinity, since it depends a bit on the alk level.

What salt mix are you using?

 

[PCygni]

That method sounds fine, but you may need to boost alk faster to get there. The demand might increase as you add alkalinity, since it depends a bit on the alk level.

What salt mix are you using?

Dear Randy,

Not to hijack the thread but.... I use Reef Crystals and my alk generally runs in the high 11's (if my test kit is to be believed) is that too high? And does high high alk translate into lower ph? I'm still having trouble grasping that relationship. My Oolite sand bed seems to be congealing in a few places could this be a product of too high alk?

I know, so many question.....

Thanks in advance.

Really enjoy reading your comments here and on the 'other' site

 

[Randy Holmes-Farley]

Thanks!
High alk would lead to higher pH. Are you dosing anything?

That alk is ok for all but ULNS systems, but may be contributing to the sand problem.

It is high from the salt mix and low demand, if you are not dosing anything.

 

[Bernardhny]

Testing this morning

I am using Red Sea Coral Pro.

I will check the Alk this morning and give my second dose to raise it up to the 8.5 level. Of course my goal is to figure out how much dosing to do and to try to keep Calcium, Alk and Mag in check via dosing. I never seem to get everything to stay in check.

That method sounds fine, but you may need to boost alk faster to get there. The demand might increase as you add alkalinity, since it depends a bit on the alk level.

What salt mix are you using?

 

[PCygni]

Early this year when my tank was a few months old I first started testing for ca, mg, and alk (with Salifert kit). My first readings showed a deficiency in ca and mg (alk even then was running at 12) which I attributed to a feather duster explosion and coraline algae really starting to come on strong (only a few frags in the tank); so I dosed Birghtwell ca and mg for a while and switched over from IO to RC. All this rapidly brought my ca into the mid to high 400s and my mg up to the high 1300's and seemed to lower my alk slightly. I left off dosing as soon as I started using RC as I found it maintained my ca, mg and alk at the levels stated above. I have a 75 DT with a 30g sump, protein skimmer, gfo reactor, carbon reactor, etc. My bio load is pretty light, 3 fish and about 12 frags. The corals with the exception of a couple lps seem to be doing well, particularly my orange montipora digitata which seems to grow like a weed. My sand bed however does not look good. It seems to forming a pasty pealing crust . After reading some of your other posts I began to suspect that perhaps high alk levels were causing this. I have contemplated switching over to Tropic Marin as I understand it has much lower alk, but I am loath to start jacking around my water parameters and set back my corals.
As you can probably tell I'm pretty new to all this (my tank will just be a year old in October) so any assumptions I make might be erroneous. Not sure how to proceed.... Thanks....

 

[Bernardhny]

I just tested calcium and Alk. Calcium is reading at 540 and Alk was at 144 ppm (8.02). I am going to check both Alk and calcium with a second test kit. Not sure I understand the calcium increase overnight.

 

[Randy Holmes-Farley]

I just tested calcium and Alk. Calcium is reading at 540 and Alk was at 144 ppm (8.02). I am going to check both Alk and calcium with a second test kit. Not sure I understand the calcium increase overnight.

If you didn't add it, then the difference is test kit inaccuracy. It never rises on its own.

 

[Bernardhny]

I started dosing alkalinity tonight. My calcium is holding and I am not at the point of dosing to keep it up. I am starting my Alk dose lower than I need just to be safe. I don't want a spike and start precipitating.

I am going to measure calcium and Alk nightly to make sure nothing goes out of whack. Nervous as hell. Last time I tried this was disastrous

 

[Randy Holmes-Farley]

Well, it sounds like the approach is a good one.

 

[Bernardhny]

Tonight I measured the alk prior to the Doser turning on. My alk dropped from 149ppm to 129ppm. Is the 20ppm drop per 24 hours normal?

I have not tested calcium yet or magnesium today. According to the BRS calc I should need to dose 54ml to go back up. That seems like a lot.

Thoughts?

 

[Bernardhny]

Calcium was down to 495. I will measure alk again in an hour (Doser just ran for 23ml)

 

[Bernardhny]

Last update. Dosing 23ml brought the all up to 138ppm from 129. Calc says I should have put in 53ml to get to 150ppm. Really seems like a lot. Ran the Doser manually for a bit and got alk to 140ppm. Increased Doser time from 16 min to 40min which should result in 44ml of alk dosed per 24 hours. That should keep alk around 8.4. I eect that when I test tomorrow at 9pm that the ppm will be down to around 133 ppm. After dosing 150ppm.

The question becomes should I split the dose up to 2 or 3 smaller doses to not experience such a wide change in alk ?

 

[Randy Holmes-Farley]

Tonight I measured the alk prior to the Doser turning on. My alk dropped from 149ppm to 129ppm. Is the 20ppm drop per 24 hours normal?

I have not tested calcium yet or magnesium today. According to the BRS calc I should need to dose 54ml to go back up. That seems like a lot.

Thoughts?

That's equivalent to 1.1 dKH. That's not unusual. Folks often need 1-3 dKH daily.

If you have a dosing pump, yes spreading out the dose over several times during the day/night with a timer is a good plan for a variety of reasons.

 

[Bernardhny]

Predicted alk drop occurred exactly as I thought it would. I have not split the dosage yet but I am thinking of three doses of equal amounts. 9 am , 3pm and 9pm.

Calcium is dropping slowly but not down to the 450 range yet. I am dropping about 15 ppm per 24hrs. When I get down to 430 I am going to start dosing.

 

[Randy Holmes-Farley]

OK, sounds good.

Happy Reefing.

 

[Bernardhny]

Minor setback. After a few days of predictable results my alk was way off. I had separated the doses (53 total minutes) to 3 15 min sessions (cutting back a bit to 40ml. When I went to test before the 3rd dose even went in the alk was 179 ppm. If I would have let that final dose go in the alk would just go even higher.

I adjusted the dosage to 8 min sessions 3 times per day. Cutting the total dose by half and skipping the third dose tonight.

Am I over thinking this? I expected the ppm to be around 140 before the final dose corrected to the desired 150 ppm.

As for calcium I was down to 394. I used the brs Calc and it said I needed like 110 ml of calcium. That seems a huge amount.

I manually added 3.5 ounces of calcium and will measure the drop tomorrow. This is so frustrating.

 

[Randy Holmes-Farley]

Figuring out doses is not exact science. The more you dose, the higher the demand in the tank, so trial and error often works better than trying to figure a perfect dose.

Also, do not adjust calcium doses after only a day or two. The kits are just not precise and accurate enough.

Base the dosing of equal parts on the alkalinity reading. If, after a substatial period (a week or two or more), calcium is not where you want it, then adjust that dose if you think you need to.

 

[Bernardhny]

Randy,

So you are saying if my alkalinity dosing becomes steady at 24 ml per day I should dose 24 ml of calcium as well?

 

[cginter]

Yes. I bet randy has answered that question 100 times in the past two weeks (I asked the same question).

If your using a two part solution, you should dose both part (A&B) the same amount. The cal solution takes a lot more solution to raise, that's why you typically don't see a change on your test kits.