How much is too much 2 part?

[wharfrat48]

I'm currently adding about 250ml of Randy's 2-part per day. This seems like alot to me but I'm not sure. I have a sparsely stocked 75g tank with about 100g water total when I include the sump and refugium. I am also dosing saturated kalk for all top-off water (about 5g/week). Parameters are pretty steady at pH 8.2, 9kdh and 400Ca and 1300Mg

Thanks for any input

 

[Randy Holmes-Farley]

Which recipe?

 

[wharfrat48]

The first one (more concentrated).

 

[Randy Holmes-Farley]

That is a fairly large amount. Alkalinity is stable for a week or so with that dosing?

Have you noticed any preciptiate on anything?

Good coralline growth?

 

[wharfrat48]

I started using a dosing pump about 3 weeks ago. It's been running about 10ml/hr (after calibration) for about 2 weeks. My Alk went from about 7.5 to 9.0 but has now been stable for 10 days or so. My Ca did get pretty low (I'm not sure why) it had always been 420+ but went down to about 350ppm. I added addtional Ca to bring it back to around 400 over a few days.

Decent corallline growth, but nothing crazy. I have maybe 6-8 SPS frags none of them bigger than a baseball (most half that big). A big torch, hammer and open brain, and xenia out the ying yang .

As for precipitate, I have noticed some on the bottom of the glass on my sump (a thin film) where I dose. This is really stuck on the glass (like coralline). I have alot of what I think is dietris in the other part of my sump (upstream from where I dose). Ca and alk ppt would be attached not loose, correct?

I can't think of anything else. I have always had low alk and was hoping this doser and the 2-part would help raise it, but I certainly don't want to crash my tank. Thanks for all the help.

PS Everything (fish and corals) look normal/good.

 

[Randy Holmes-Farley]

I guess that I would keep it up until either the alkalinity rises too much, the pH rises to much, or the precipitate seems to become problematic. Otherwise, there is no real problem with large doses.

 

[wharfrat48]

Well now I'm A bit concerned. Checked the Alk again last night and it hasn't gone up but maybe even down a bit. I looked for signs of ppt. and might have convinced myself of seeing some white powdery material on the rocks in the main tank.

I also played around with the online calculator, and it seems my alk and ca should be going up pretty fast. The only thing I can think of is ppt. removing Ca and (bi)carbonate from my system. What would make these fall out of solution (pH 8.1-8.3)? Would you recommend stopping the use of kalkwasser for my top-off?

I'm very puzzled.

Thanks for your help.

 

[Randy Holmes-Farley]

The things that lead to excessive precipitation are high calcium, alkalinity, and pH, and low magnesium.

pH is one of the biggest drivers. A rise of 0.3 pH units is equivalent to a doubling of alkalinity or calcium.

None of your values would seem to be a concern as reported. Maybe you have a kit error?

 

[wharfrat48]

I have duplicate kits for Ca and Alk, they are usually spot on with each other, but I'll double check tonight.

Not sure what you mean by "A rise of 0.3 pH units is equivalent to a doubling of alkalinity or calcium". I have a pH swing of 8.1 (morning) to 8.3 (evening). Would measurments made in the morning be 66% lower than those taking in the evening?

I really do appreciate your insight and your time. RC would not be the same without your expertise.

 

[Randy Holmes-Farley]

In terms of the likelihood of precipitating calcium carbonate as indicated by the calcium carbonate supersaturation index, these are all equivalent:

Ca 400 ppm
alk 7 dKH
pH 8.5

Ca 800 ppm
alk 7 dKH
pH 8.2

Ca 400 ppm
Alk 14 dKH
pH 8.2

Would measurments made in the morning be 66% lower than those taking in the evening?

In terms of calcium carbonate supersaturation, yes.


I really do appreciate your insight

Thanks.

 

[wharfrat48]

Ahhhh..... now I get it

 

[Randy Holmes-Farley]

I wouldn't worry unless the precipitate becomes evident to someone not looking for it.

 

[steve the plumb]

I to dose randys formula 2 part and auto top off with kalk.It takes a bit of dialing but once you get it it should be constant.I use the aqua medic doser to dose the 2 part formula.I find it works well.I to overdosed the first time trying to figure out how much and how often to dose.The kalk I find doesn't affect the alk boost greatly.I used to dose just kalk and found dkh at 7 to 8.4. it never went higher than that.My calcium levels stayed at 400.I would add cal(liquid form) only to boost calcium but I would ad it once a week if that.I added because I wanted to finish the bottle.I started dosing randys cal with the dosing unit aswell.I dose the calcium alot less.I find kalk dosen't boost calcium levels but maintains them.I have added at least 6 more acros in the last month so the demand went slightly higher.I still think this is the best way to maintain alk cal and ph levels without the use of a calcium reactor.I find its also safe and even if you over dose you can still keep corals alive and not damage or kill everything in the tank.

 

[wharfrat48]

We'll I just checked my tank again and now I'm totally confused. After slowing my 2-part drip to 125ml/day (vs 250ml/day) yesterday my Ca is up to 460ppm, alk down to 7kdh, pH "normal" at 8.3, also check my salinity and it has gone up to 1.0265 from 1.025. Any idea whats going on?

 

[steve the plumb]

did you still top off with kalk?Is the alk from the same batch of alk water or do you make a new batch every day.

 

[wharfrat48]

I am still topping off with kalkwater with an auto-top off system. And my 2-part additions are done with an infusion pump @4ml/hr 24 hr a day (about 100ml/day from 250ml/day). I guess I'll just add some additional alk solution until I get back to around 9-10 dKH and maybe bump up my dosing rate to 150-200ml/day. Everything in the tank seems to be doing fine, I would just like to get everything stabilized.

Is salinity related to any of this? It had been stable at 1.025 for years.

Thanks again

 

[Randy Holmes-Farley]

Any idea whats going on?

I would focus on trends, not day to day changes which are prone to significant testing errors. Trying to interpret such changes is often fruitless. If calcium continues up, then stop it for a few days, or dose less of it.

 

[steve the plumb]

I have found adding more kalk doesn't raise the alk levels.You can make your alk dose more potent by adding more soda to it .You have only been dosing for 3 weeks so its still fairly new.Once you get the dose down pat your levels should be stable.Are you adding more corals to the tank or have you added more corals within the last week.More corals more consumtion.