2 Part Dosing Issue

[Mando77]

I am trying to figure out why I am having to dose so much 2 part. Before Thanksgiving I was dosing 90 ml of two part daily and my calcium and alk is still going down 12 ppm a day. And this is for a 29 gallon tank. My Calcium was 420 alk 10.2 and with 5 days dropped to 360 and 7.8. BRS told me this was due to precipitation. My dosing pumps are dosing directly over my return pumps. My Mag is also high. Does anyone else have to dose more than the recommended amount? Just trying to figure out if I am doing anything wrong.

[John]

How are you dosing, continuously throughout the day or at one shot? May be an issue of when you are testing versus dosing...added any calcium hungry corals lately? May be test kits too...

[Ryan S]

I only dose 25ml/day of alk and cal in my 150g reef. 90ml/day for a 29g seems very high.

 

According to BRS's instructions, 1ml per gallon is for "Numerous full sized SPS colonies and clams". You are dosing 3x that.

 

I am not sure what's going on. Doubt it's evaporation. You can't be evaporating that much.

 

Are you sure the 1g jugs of Alk and Cal were mixed accurately and not dilluted too much? Are the tubes clear and not clogged? (IE you think they are on for 90 minutes, but really if they are clogged, very few drops get through, or none at all.) Last guess is test kit accuracy. Are you sure the alk/cal tests are accurate/not expired, etc.

[miggs76]

This is a good question. I'm having similar issues but only with ALK. Seems my calcium remains stable but my ALK drops about 5 ppm per day. Does ALK drop just from evaporation?

[Origami]

Alk does not drop from evaporation. If anything, evaporation concentrates calcium and alkalinity. What test kits are you using? Is the two-part commercial, pre-mixed, or DIY mixes? The alk and calcium drop are asymmetric. It can't all be due to precipitation. For example, a 60 ppm drop in calcium due to precipitation would require consumption of 8.4 dKH alkalinity. How are you measuring magnesium? Any chance that you can get another aquarist nearby to test your water?

[Origami]

This is a good question. I'm having similar issues but only with ALK. Seems my calcium remains stable but my ALK drops about 5 ppm per day. Does ALK drop just from evaporation?

Balanced consumption consumes 20 ppm calcium for every 2.8 dKH alkalinity. (2.8 dKH alkalinity equates to 140 ppm CaCO3, which is probably the reading that you're reporting.) Thus, your 5 ppm alk drop per day, if due to consumption, would result in a drop of 0.7 ppm calcium which is too small for our test kits to measure from day-to-day. One can also have unbalanced alk drops if you are managing elevated nitrates using water changes.

[Guest]

I have two test kits. I have the new red sea pro for Alk, Cal and Mag and I also have an older API kit I use to check agianst. They say the same thing with the Red Sea being more exact. I dose 2 part with BRS solution and I also use their 1.1 ml dosing pumps. Corals are doing great tank running fine, its just a darn sponge. Can't figure out why it needs so much. My goals are to keep Cal around 460-480, Alk 12 DKH and Mag 1400-1500. It does 1 ml a minute so its slow and steady and I dose at night around 3 AM.

[Guest]

My tank is also mainly SPS.

[Origami]

Maybe it's an obvious question, but are your two-part reservoirs actually depleting at a 90 ml/day rate? That is, are you going through a liter every 11 days? If your peristaltic tubing is fatigued and flat, your dosing accuracy may be off.

[Guest]

I am going to check that, but the set up is fairly new. It works as soon as I turn it on through my apex. I just thought the issue was I had way to many SPS. and yes 90 ml a day and cal and alk still dropping.

[OldReefer]

I think Tom is on the right track. Tubing can go bad, and stuff can just get plugged up. Make sure you are actually putting out as much fluid as you think. Just stick the output into one of those BRS 100 ml cups and let it run for an hour.

[Ryan S]

I think Tom is on the right track. Tubing can go bad, and stuff can just get plugged up. Make sure you are actually putting out as much fluid as you think. Just stick the output into one of those BRS 100 ml cups and let it run for an hour.

Bill, how much alk and cal do you dose each day?

[OldReefer]

 

Bill, how much alk and cal do you dose each day?

 

I dose about 330ml of BRS Ca and 240ml of BRS recipe 1 Alk. That is in my 150 Display. My over-crowded 50 gallon Frag tank takes about 100 ml of each.

[zygote2k]

I have two test kits. I have the new red sea pro for Alk, Cal and Mag and I also have an older API kit I use to check agianst. They say the same thing with the Red Sea being more exact. I dose 2 part with BRS solution and I also use their 1.1 ml dosing pumps. Corals are doing great tank running fine, its just a darn sponge. Can't figure out why it needs so much. My goals are to keep Cal around 460-480, Alk 12 DKH and Mag 1400-1500. It does 1 ml a minute so its slow and steady and I dose at night around 3 AM.

FWIW, on the 90 SPS tank that I maintain, when we were dosing manually 2x per day, there was a much greater amount of 2 part being used. When we switched to a doser, that amount was cut nearly in half. I believe the hand dosed amount was 90ml/day and the doser amount is currently 50ml/day. The doser delivers this amount over a 24hr period- not over a 90minute period like yours. 480 Ca, 12dkh, and 1500mg seem abnormally high too. The best I am able to get and keep steady for over a year is 400-425 Ca, 8-9 dkh, and 1300-1400mg. I have written records for last 3 years to show these results.

[surf&turf]

I was also curious as to why you were striving for such high numbers.

[Guest]

I just try and keep high for SPS growth. I'm going to test my BRS pumps tomorrow.

[Steve175]

I also think you are striving for alk and ca levels which are too high. When I used 2 part, dosed equal volumes of Calc and Alk to maintain latter ~ 9. Even there and dosing with a liter meter 24x7, I had frequent precipitation and high pH which ultimately led to my switch to a calc reactor (which was worth the trouble of switching)

[basser9]

This is a very commen problem with 2 part i had a very similar problem.

My pumps were getting covered with precip and sticking and alk was hard to keep up.

The problem was helped by dripping it in the tank and not in the sump.

The problem wasnt dripping the calcium it was the carbonate.

I find that the constant dripping of sodium carbonate is worst sometimes then just dumping it in at once.....

Dosent seem like that would be the case but i have dosed diy 2part on and off for 12 years in alot of different setups.

Weird thing is some of my setups had no problem......hard to put a finger on why sometimes this happens.

[John]

Figure this out yet?

[Guest]

BRS said to let tank sit a while without dosing to see what it drops to. So i'm monitoring and will adjust as needed. Hope to figure this out. Will take a few more weeks.

[matt]

How are things going? Did you get it worked out? cheers