Water Chemistry -- I need help

drdude05 · 11-09-2006, 09:30 PM

Ok ... I am about to start beating my head against the wall. I have been trying to put my tanks water chemistry back in balance for the past three weeks. I initially left the tank alone after the crash to let it cycle again and hopefully correct alot of stuff on its own and other than water changes I tried not to do a whole lot to make things worse.

Now that the cyano and hair algae blooms were over I have been trying to get my water chemistry optimal again. Prior to the crash I had readings of:
SG - 1.024
pH - 8.2
ammonia - 0
Nitrate - 0
Phosphate - 0

As of tonight the levels are:
SG - 1.024
pH - 8.0
ammonia - 0
Nitrate - 0
PO4 - 0.2
Alk - 2.74
dKH - 7.7
Calcium - 350

I have done weekly 32 gallon water changes (tank is 180 gallon with 60 gallon sump) with instant ocean and RO/DI. I have finally hooked up my calcium reactor (it is a single chamber) and the internal chamber pH is 6.8 (roughly ... it has been bouncing around a little as I have been trying to get the flow from my CO2 bottle regulated).

My questions ...

1. How far off am I. I know phosphate needs to be 0. I am planning on removing the carbon and phosphate sponge in my fluval as the media has not been changed for about 5 weeks ... so some of the problem is likley that the carbon is exhausted and leaching as is likley the phosphate sponge.

2. Calcium needs to be 400- 450 so I am hoping to get the reactor tuned to produce this.

3. Where does the Alk and dKH need to be? I figure they should raise as the reactor gets tuned ... but what do I do to off set the falling pH which I'm sure is do to my having a single chamber reactor with an internal pH of 6.8 and thus acidic effluent. Should I run the internal pH higher? say 7? I know ultimately that how much calcium I need from the reactor will be determined by how much my system needs. If I need to run a higher internal ph in my reactor, what do I use to increase the pH of the system? Baking soda? Two part buffer? What is a good additive to boost pH and offset acidic effluent?

4. Cyano reappeared today ... about 2 days after my last water change. With the above numbers why is it back .. again?

Help

tdwyatt · 11-09-2006, 10:15 PM

use a reef calculator to balance your ca and alk, many available on the net.

Taking a single pH test value and using it to interpret acid/base conditions in a tank is much like taking a single frame from an adventure film and trying to interpret the ending... both are as likely to be accurte. pH values will change according to time of day, in-house conditions where the tank is located, ease in air/water gas exchnges, and the presence or absence of photoautotrophs in your system. Buffer plays a small role in this, but the primary driver of system pH is the carbon dioxide concentration in the water column. To get an idea of what is happening in your system, you need to know not only the buffer concentrtion aqnd the time of day, but you need a reference for those times, e.g.: a morning value (lights on), mid-day mid afternoon, nd a lights out value in addition to a few overnight spot checks for spot checks. This alows for the visualization of trends in the system, making much more sense for our evaluation of the system than would a single value.

Personally, I don't think you have any issues for now, get the Ca reqactor going and start testing THE EFFLUENT for now, and do not worry about the tnk until you have specimens in the system. Once you get closer to placing your replacement specimens in the system, use the reef calculator and bring the tank parameters up with two part additives, then run for a week and see how it goes.

Set up the reactor, test the effluen, and post some numbers on this, then we can start talking.

Don't caase numbers for now, you'll have to tweak the reactor as your hermatypic pops grow and you add more specimens anyway.

HTH

drdude05 · 11-09-2006, 10:19 PM

If you need more data points the pH over the last 5 days has been:

AM PM
Sunday - 7.98 8.14
Monday 8.04 8.21
Tuesday 7.92 8.08
Wed 8.06 8.14 Started up the reactor here
Thurs 7.88 8.0

drdude05 · 11-09-2006, 10:27 PM

As for the reef calculator ... how do you choose "calcium reactor" as your desired product for raising calcium alkalinity? Or are you supposed to use a different "product" to balance a mismatch produced my the reactor?

tdwyatt · 11-09-2006, 10:28 PM

initialy use the 2 part of choice, as it takes a LONG time to get to balance with a Ca reactor.

Once the system is up and your reactor is tweaked, you can use the calculator to determine your effluent rate based on your effluent test results.

drdude05 · 11-09-2006, 10:35 PM

I think I see. Additives do the "changing" of values ... reactors "maintain" those values once changed. If the values don't stay stable the reactor isn't tuned to maintain them to keep up with the demands of the system as a whole.

tdwyatt · 11-09-2006, 11:00 PM

Quote:

Originally Posted by drdude05

I think I see. Additives do the "changing" of values ... reactors "maintain" those values once changed. If the values don't stay stable the reactor isn't tuned to maintain them to keep up with the demands of the system as a whole.

YES!!!

mg · 11-09-2006, 11:08 PM

Also I am guesing you are measuring ALK in meq/L? DKH are units of alkalinity, I believe the multiplier is 1meq/L=2.8DKH. These 2 test are most likely measuring the same thing. What are you using?

drdude05 · 11-09-2006, 11:10 PM

Do you have a two part that you recommend to use to increase the calcium and alkalinity? I have been looking at a few of the calculators and it seems like its going to take alot of two part to get my caclium up to the 420-450 range from 350 same deal for my alk.

drdude05 · 11-09-2006, 11:10 PM

Salifert

tdwyatt · 11-09-2006, 11:21 PM

Quote:

Originally Posted by drdude05

Do you have a two part that you recommend to use to increase the calcium and alkalinity? I have been looking at a few of the calculators and it seems like its going to take alot of two part to get my caclium up to the 420-450 range from 350 same deal for my alk.

Check out Randy (Farley-Holmes) 2 part home brew, or get some pickle crisp (food grade CaCl2) and some baking soda, cheap, effective, safe in marine systems.

drdude05 · 11-10-2006, 10:14 AM

Ok, I just want to check my logic here. My plan of action will be to:

1. Continue tuning my reactor until the effluent matches the levels I want to "maintain" ... hopefully balance in ca and alk.

2. Use a two part additive to elevate the calcium and alk levels in the tank by using a reef calculator to figure out how much of each to add in order to raise them in a balanced fashion. Do this slowly.

3. Continue with weekly water changes to try and continue to remove phosphate.

drdude05 · 11-14-2006, 07:16 PM

Ok, next question/problem. I have been tuning my reactor as suggested ... testing only my effluent from the reactor ... and right now the effluent has a pH of 7.7, Calcium of 420, and an alkalinty off the chart.

Why?

I thought a calcium reactor was supposed to allow for dissolution of reacotr media to all for a BALANCED dosing of calcium and alkalinity.

Why is the alkalinity above what my salifert test can measure ( > 16dkh or 5.71 meq/L)? According to the reef calculator I am using the alk should be 2.95 for a calcium of 420.

More importantly, what do I do to fix it?

drdude05 · 11-14-2006, 08:43 PM

I just rechecked my tank levels and they are as follows:

Mg - 1140 (was 1140)
Ca - 350 (was 350)
Alk - 3.54 (was 2.74)
PO4 - 0.6 (was 0.2)

I did a water change of 40 gallons on Sunday. Replaced the carbon and phosphate sponge in the fluval. I have been blasting the rocks with a powerhead and have been cleaning up the snadbed and last remnants of cyano. I'm sure this is probably where the phosphate increase came from.

drdude05 · 11-15-2006, 11:59 AM

Tom ???? Don't leave me now.