View Full Version : How much 2-part per week?

12/12/2010, 02:19 PM
I recently setup a two part dosing pump and hooked it to my reefkeeper to be controlled by the pH. I have a clam, but very stony corals as I lost nearly everything when the pH crashed. even the coraline seems to have died back. I'm making Randy's Two part (2 1/4c baking soda per gallon). I knew I would use a lot getting the pH back up to normal. I currently have the meter set to turn on at 8.05 and off at 8.15. Week two started at around 8.0, which is when I bumped it up. I've gone through a gallon (1g Ca, 1g Alk) in a week, with very few stonies. Is this normal? I'm startign to consider buying some 5g containers to mix the alk and ca in so I can dispense it each week instead of making a new batch each Sunday. Is this a good idea?

recap: How much 2-part do you estimate I should be going through in a week? & Is it a good idea to mix up a bigger batch and then dispense it weekly instead of mixing a new gallon each week?

12/12/2010, 02:41 PM
i havent used that 2 part forumla before.. but if you added a gallon--- sounds like a lot --- and you didnt notice a chance in alk and calcium your magnesium might be too low. low mag creates problems with maintaining high alk and cal.

I would check that first before dosing again. Its an annoying test, might want to have a good lfs do it for you if you dont wanna get the kit.

12/12/2010, 02:41 PM
Its going to vary between every tank. What I did was start an Excel sheet with measurements and how much I was putting in. When levels got where I wanted, and I experimented with different dosages, I nailed down exactly how much I should dose.

This, of course, was when I was dosing Magnesium and Calcium, but I'd expect the same results from doing so. You might burn through a test kit quicker than normal, but it'll help nail down the dosages for your individual tank.

Once you add more coral and coraline starts taking off, you'll probably have to start dosing more calcium down the road.

12/12/2010, 02:46 PM
Thanks for the thoughts. I checked my mag the first week and it was around 1400. That was one of my first thoughts as well.

Is it possible to overdose without having your pH go above 8.15?

12/12/2010, 02:47 PM
Not sure if going by PH is the best way to dose, yeah your PH will rise when you dose alk but I think your better off testing your alk then wait 24hrs and test again to see how much dropped in a day, then use the alk calculator to figure out how much to dose daily instead of going by the PH. If your battling low PH there could be other reasons for it rather than low alk.

12/12/2010, 03:04 PM
I just found my salifert Alk test and it tested off the chart. I added the entire reagent and the liquid was still blue. Either my test kit is bad or my alk is off the charts! I don't know if I have another test kit, but I'll keep looking. There is no where local to buy one right now. Suggestions?

12/12/2010, 03:25 PM
1 gallon is alot of two part to dose in a week, most likely your alk is off the charts after dosing that much, stop dosing for now until your figure out what your alk is at. Going by PH isn't a good way to try to figure out how much alk to dose.

12/12/2010, 03:31 PM
Yea, no more two part for now.

I just tested the Ca using API and stopped after the reading should have been over 600 and it was still pink. Both numbers must be through the roof. Is this going to damage the tank?

12/12/2010, 03:35 PM
Its possible to have damaged some corals, it's best to stop dosing and let the alk and cal come back down, it's best if the alk drops slowly to not shock anything more than its already been, how do the corals look?

12/12/2010, 03:50 PM
I had very few corals left. My bubble coral is withdrawn as are my anenomes. I noticed ick on my fish yesterday evening, which is what made me think something may be wrong. My cleaner fish is proving his worth. My next question was going to be if I should do a massive water change or let it drop naturally, but you beat me to it. :) I'll keep a close eye on it and keep my fingers crossed that it drops at a good rate for the inhabitants. I'm guessing that my house has a high CO2 content, which doesn't surprise me much since it was built in 2000. Unfortunatly, the tank is in the middle of the house, which is an open floor plan. I can't think of a way to run an air line outside...

I appreciate the help.

12/12/2010, 04:05 PM
I'd do daily water changes to get your levels down to normal. levels that high can and will kill your corals especially if left long enough. I would do a daily 10-20% water change with something like plain instant ocean that has lower levels of alk and calcium. Remember not to adjust things down too fast as nothing good happens quick.

12/12/2010, 04:23 PM
... the pH value is affected by more than one factor. Alk is one, but the others are accounting for probably the same. Read Randy's articles on Alk, there is a lot to learn from there. If I were you I will stop chasing pH by adding part 2. You will end up again crashing your tank and burning the rest of your corals. Go buy a good test kit (Salifert, Elos, LaMotte) and check your Alk every other day. Set a target and using the calculator see how much you will have to add. Since baking the sodium bicarbonate adds some variation to the end result go ahead and correct (by trial) what the calculator will say (usually a few ml no more).

Do a 10% water change for now to lower a bit the values. I have a 75g total volume and I run a Sulfur denitrator (notorious for dropping the Alk) and I add about 35 ml daily.

hope it helps,

12/12/2010, 04:39 PM
35ml is much less than I dosed! Thanks for a number. When I start dosing again, I'll do lots of testing as set the doser instead of using the controller.

12/12/2010, 04:39 PM
I might use a pH controller to shut off alkalinity dosing if the pH is too high, but I wouldn't control the dosing based on pH otherwise. That approach could lead to a number of problems, including an alkalinity overdose.

It's unlikely that the pH dropped low enough to kill your animals unless some sort of extreme situation was involved. What exactly happened when you lost your clam? I suspect other factors were involved.

Each tank has a different alkalinity consumption rate, so you'll need to do some tuning. 2-3 dKH per day is fairly common in a lot of tanks, for example.

12/12/2010, 04:45 PM
I still have a clam. My pH was dropping to 7.4-7.6 range at the worst time. I was working with my seahorses and raising the fry over this summer and neglected this tank (125g). I'm trying to get it back on track, but it looks like I over did it.

12/12/2010, 04:47 PM
I don't believe that 7.4 is possible unless the air around the tank was very, very stale. I suspect a measurement error.

12/12/2010, 05:01 PM
With a 125 gallon tank I don't find that to be a ridiculous amount of consumption. I use 140 mL of Alk/Calcium. I also do 10% WCs weekly.

12/12/2010, 05:12 PM
... at a rate of 140 ml a day one gallon will last 27 days = 4 weeks ! :beer:


12/12/2010, 05:17 PM
I consider that my DT is 50 gallons less....Still not a mature SPS tank either. I've seen where some larger tanks have some crazy consumption rates.

Either way, I've got 2.5 gallons of alk/calcium in my cabinet for dosing so I have over 2 months worth;)

12/12/2010, 05:18 PM
...and I put in two gallons over the past two weeks (gallon each week). I'm mixing water for a 10-20% water change. I guess the good news is that I won't need to mix a new gallon of each up every weekend.

12/12/2010, 06:13 PM
The 2 part should only be dosed based off your needs. I bought the bulk 2 part and havent been able to use much because my alk and cal stay relatively high without any maintaining. The key is keeping a balance between cal, alk, and magnesium. I dose mag once a week to keep my level around 1500. I noticed immediately that my corraline bloomed back once the mag was maintained and found out that corraline algae is very absorbent of mag from a friend. If youre having trouble keeping your cal and alk high enough, change salts. After trying over a dozen types I found that coralife kept my levels really high and didnt impact my ph, no2, or phos.

12/12/2010, 06:18 PM
You must not have a lot of coral, especially LPS/SPS. They consume alk and calcium while growing and the mag's main purpose is to keep the two supplements from forming precipitate before the coral takes it in.