2 part dosing... Excessive.... or just me?

[Eric83]

Mixed it according to BRS directions. Have made several jugs at this point, so I'm pretty certain its not a one off mixing error

Just had the 4th round of alk dosing go in on the new schedule. I measured 15min before (7.4dkh) and 15min after (7.9dkh). Pretty much just bouncing around in the range I was already in. In the 4 doses there would have been about 160ml added to the tank. According to BRS calculator that should be enough to increase dkh by 3.0. So it doesn't look like dosing times alone was the issue. Gonna keep there alternating schedule once I resume dosing, but for now I'm going to turn it off completely.

When I was at my LFS they said up to about 2.0dkh swing would be fairly "safe" as a one time type of event rather than on going daily swings. One of the guys at the shop had a personal experience with a crash of about 4.0dkh and says nothing died, but obviously wouldn't recommend it. BRS seems to go with 1.4dkh is "safe" on a daily basis. I realize we all aim to minimize swings over the long term, cause stability is king. But in my situation - IF I get a rapid drop upon turning off my dosing pumps- how far do I let it go before I start dosing to keep it from dropping too far/too fast.

 

[Steve Fast]

Interesting. How about I share my experience involving a similar issue? First some background. All of my tanks have mostly soft corals and I dose sufficient 2 part (in equal amounts as per guidance found online... I can try to find references if you would like) to account for a loss of 2.2 dkh per day. While I do not get the same precipitation you allude to, my dosing strategy is to dose the same amounts at the same interval offset by 1/2 the time interval. That is, for example, dose every 12 minutes where one starts on the hour and the other starts at 6 minutes off the hour. With this schedule and dosing amount, things have been stable now for 2 months... relieving significant anxiety in me.... Also I dose magnesium at ~1/6 of the other two in my top off. See http://www.bulkreefsupply.com/instructions/article/Instructions-for-Bulk-Packaged-Materials for details....

Hope this helps.

 

[dgrigor02]

If you haven't done so already. Capture the dosers effluent into a measuring cup for a full day and verify the amount per day is what you think it should be dispensing.

 

[Eric83]

Dosers were calibrated no more than 2 months ago. And based on running through 2.0L of solution every 4-5 days, I don't think calibration is my issue.

 

[john.m.cole3]

This just gets weirder. 460 ml a day is enough to run a well stocked 300 gallon + tank. So you have your doser calibrated, you have consistency mixing the elements (no recipe concerns), your doses don't overlap... Do you have corraline growing on everything? Hmmm.......

What if we really mix things up. Maybe you could buy some pre-mixed elements and dose by hand. this would eliminate any automation errors.

Final thought for now. Turn everything off after your last dose. Get the tank to 7.9 dkh. Leave the doser off for 24 hours then re-test. Have we already questioned whether your test kits are accurate? I'm dying to get to the bottom of this.

 

[mts2005]

I have a 210g and had the exact same problem. So frustrating having to break down and clean equipment on a monthly basis, pump failures due to seizing from precipitates. The solution was to stop dosing for several days and then restart at no more than 0.3ml/gal/day for each the calcium and bicarbonate. Just trust it and resist the urge to increase if there are some initial parameter swings. Address those with some frequent water changes until you get back on track. After I made theses changes, I clean the pumps every 6 months as a precaution and see little precipitate. Good luck

 

[Eric83]

This just gets weirder. 460 ml a day is enough to run a well stocked 300 gallon + tank. So you have your doser calibrated, you have consistency mixing the elements (no recipe concerns), your doses don't overlap... Do you have corraline growing on everything? Hmmm.......

What if we really mix things up. Maybe you could buy some pre-mixed elements and dose by hand. this would eliminate any automation errors.

Final thought for now. Turn everything off after your last dose. Get the tank to 7.9 dkh. Leave the doser off for 24 hours then re-test. Have we already questioned whether your test kits are accurate? I'm dying to get to the bottom of this.

I do not have visible corraline yet, tank has been up for maybe 2 months post cycle... hope I see some soon though. Although I'm guessing my alk problems aren't helping.

I have a 210g and had the exact same problem. So frustrating having to break down and clean equipment on a monthly basis, pump failures due to seizing from precipitates. The solution was to stop dosing for several days and then restart at no more than 0.3ml/gal/day for each the calcium and bicarbonate. Just trust it and resist the urge to increase if there are some initial parameter swings. Address those with some frequent water changes until you get back on track. After I made theses changes, I clean the pumps every 6 months as a precaution and see little precipitate. Good luck

Good to hear, gives me hope

 

[Eric83]

4hrs after last dose - 7.0dkh down from 7.9dhk right after last dose

hopefully it levels off a bit.... 0.9dkh over 4 hrs seems steep

Ill test again first thing in the morning

 

[Eric83]

12hrs after last dose - 6.6dkh. Glad to see the drop slowed down.

pH has also droped from the 8.0-8.1 range to about 7.9

since everyone always recommends 7.0 minimum - how many days can I safely stay below 7.0?

 

[BigJim]

I would try to keep it around 7. Maybe start by dosing around 2 ml per hour and see where it levels off. What type of rock are you using? I have heard people say that certain artificial rocks absorb alk, but I have not experienced it myself.

 

[Eric83]

But dosing at this point would kind of defeat the purpose of not dosing... wouldn't it? Haven't hit the 24hr mark yet, so if I was following the advice given here and other forums to a T.... I shouldn't be testing for another 6hrs (the 24hr mark).

I have roughly 30lbs of rock from BRS, their economy stuff. I also have roughly 12-15qty 2"x 2" marine pure cubes in my sump, they are suppose to have a crazy amount of surface area for their size. I'm not sure if a tank can have too much surface area or not, and if it could play a roll in the issue I'm seeing.

Before I begin dosing again. I am planning to remove as much of the white chunks/flakes from acrylic in addition to the stuff that's already flaked off on it's own and sitting loose on the bottom of the sump. I have noticed on prior cleanings that when I disturb this stuff my alk has a brief spike. I want as much as possible gone since I don't know if it's presence further aids in more precipitation. After all the cleaning is done I plan to do a 20% water change.

 

[BigJim]

So are you waiting to determine how much alk you use in 24 hours? I didn't quite catch why you were waiting 24 hours. If so, you can stick with that plan. I can tell you I lost some LPS in the past when my alk dipped below 6, so keep testing and keep an eye on your corals. I have a marinepure block and spheres in a 155 gallon sps dominant tank and dose less than 20% of what you are dosing.

 

[dragon99]

Maybe try using limewater instead of 2-part for a few days? Something has got to be out of whack with the dosing for you to be getting that precipitation.

 

[markalot]

Question,

the BRS makes equal strength parts (so to speak) so you should be dosing the same amount of both parts based on Alk usage. Ca reads a little high, maybe, so have things been out of balance? Do you have a current picture of your tank so we can see what kind of usage might be expected?

In a full SPS tank I've never used that much 2 part! I'm also alarmed by the rapid KH drop, that seems crazy as well.

 

[markalot]

I am dosing 426ml of each part daily.

Apologies, looks like you confirmed you are dosing equal parts.

IMO you should be using 30 to 40ml daily, and that would be a lot for LPS unless this is an older tank with really large colonies.

 

[tautog83]

so the tank is 2 months old, not heavily stocked and you're putting in almost 500ml of alk solution in?..thats just impossible. you screwed up somewhere (i mean you had to, no offense) did you use half cups of soda ash instead of full cups ? i dont have huge colonie of sps but its pretty stocked in an 80 gallon and and i only dose about 70ml a day . you literally are dosing 5 of the measuring cups (brs ones) at a time and are telling us that your alk isnt going up with just some lps in it .not possible .. you dont even have anything that is taking up calcium at this point. (not even coralline and to cover just 25lbs of rock you shouldnt be worried about it. you're getting that precip from probably dosing too close together or just super saturating the water . Im not totally educated in water chemistry , but without literally your tank brimming with huge colonies in a 75 gallon you will never need 500 ml of either . my suggestion is to put your dosers away for a couple months , do a big water change like 40% and just go from there

 

[tautog83]

i cant see how your alk is dropping that fast ...can you post a pic of your tank so we can see what you have inside . i mean it is possible if you have it filled but even 120ml i would imagine your tank would have to be filledd

 

[morpheas]

I would think that the rapid drop of alkalinity is attributed to precipitation (which you're seeing anyways). That's the only thing that makes sense in my mind for the rates you're describing, slow dropout reflected in the measurements you're taking. I've been scraping my brain since last night trying to figure out why there is precipitation when your magnesium for one and the other parameters are as well in line and I haven't come up with a reasonable explanation. Maybe @Randy Holmes-Farley can shed some light here...

 

[Eric83]

Half way through cleaning, decided to take a quick break.

Alk was 6.0dkh just before I started cleaning

I can guarantee it's not a mixing error on making solution, nor an error with dosers not actually dosing what I think they were. 426mls of correctly made 2 part was in fact entering my tank on a daily basis.

I know when I first setup the doser I didn't think about alternating parts so they were running at the same time for a couple weeks before I had set them up to mostly not overlap. Still no immediate visible reactions that I noticed. But that could have started the precipitation. I'm not sure how precipitation occurs (scientifically), but if it more of a cycle of events. It could be something that got started when I had dosed together and didn't necessarily end when I switched up the timing to run mostly but not completely separate. If it's a snowball like effect it could explain it.

well back to cleaning.

 

[Drauka99]

If I was betting I would put money on rapid precipitation. I had similar, was constantly raising the amount of 2 part to compensate was over 100 ml a day with 1 gallon of fully saturated kalk per day being added each day as well. when I found the sump floor with a thick mat of precipitate I stopped all dosing for several days, DKH bottomed out and did a water change. has maintained around 8.5 dkh since with very minimal doseing, 10ml a day