A must to have. Then you will know when filters and DI need changed.
15 Alk too high?
- Thread starter GpixL_
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- #322
OP
Ok Ill get that too but its not needed to test right now right? (First 50 gallons of RODI)
It is a nice to have, not necessarily a must have. Watch the color of the beads in the clear filter. They will turn from blue to brown as they get used up. The TDS meter (Total Dissolved Solids) is a bit more reliable to confirm when it is time to change the resin.
There are 2 kinds of TDS (total dissolved solids) meters.
Handheld: Fill a cup with some water then stick it in and see what it says.
In-line: You attach this to the tubing directly. This one has 2 sensors, you put one before and one after the DI resin (clear filter with blue beads). The one before tells you if the RO (reverse osmosis) membrane is working correctly (should read <10). The one after the DI resin confirms the water is clean (should read 0). They have to be installed correctly, so check YouTube for a movie (BRS has one)
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- #324
OP
Thanks for the info. It looks like a little bit of the bottom of the resin turned brown but the rest is a good color. Ill get the meter a little later when there is more brown.
Sometimes problems happen with the rodi system, especially when you’ve never used one. When that’s the case, you could be using water that’s only partially filtered, or maybe not at all.
Also, before using it, it needs to be flushed a little to get the TDS to 0. You’ll never know how much to flush without a TDS meter.
I think it’s a must.
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- #326
OP
So on BRS it says that once nitrates are present then the initial cycle has ended and there is bacteria in the tank. But I know to wait until ammonia and nitrites are at 0.
I put dr times one and only and dr tim’s ammonia yesterday. How do I already have nitrites and nitrates?
I put dr times one and only and dr tim’s ammonia yesterday. How do I already have nitrites and nitrates?
Most test kits will pick up nitrites and report them as nitrates. Don't bother testing nitrates until your nitrites and ammonia are down to 0.
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- #328
OP
Ok thanks
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- #329
OP
@Randy Holmes-Farley Is this the correct salinity/calibration? It’s 35 on the right but that’s %?Here's a recipe for a standard (for refractometers only):
Refractometers and Salinity Measurement - REEFEDITION
Title photo by R2R member Rskillz By Randy Holmes-Farley Salinity is one of the most important parameters measured in reef aquaria. It controls not only the salt balance between an organism and its surrounding environment, but also the levels of a host of ions Read more here...www.reefedition.com
Do-it-yourself Refractometer Standards
In a previous article I described how to make a do-it-yourself refractometer standard matching 35 ppt seawater, and I will just summarize that recipe here.
To provide a standard for refractometers requires a solution whose refractive index is similar to normal seawater. Seawater with a salinity of 35 ppt has a refractive index of 1.3394. Likewise, the refractive index of different sodium chloride solutions can be found in the scientific literature. My CRC Handbook of Chemistry and Physics (57th Edition, Page D-252) has such a table. That table has entries for 3.6 and 3.7 weight percent solutions of sodium chloride that span the value for normal seawater. Interpolating between these data points suggests that a solution of 3.65 weight percent sodium chloride has the same refractive index as 35 ppt seawater, and therefore can be used as an appropriate standard (Table 5).
This 3.65 weight percent sodium chloride solution can be made by dissolving 3.65 grams of sodium chloride in 96.35 grams (mL) of purified freshwater. This recipe can be scaled to any appropriate size if suitable instruments are available (36.5 grams in 963.5 grams (mL) of water, 0.365 grams in 9.635 g (mL) of water, etc.).
This concentration roughly corresponds to ¼ cup (73.1 g) of Morton’s Iodized Salt dissolved into two liters (2000 g) of water (giving very slightly more than 2 L of total volume).
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Look close. It’s not %, it’s 0/00 which is ppt.
- Thread Starter
- #331
OP
Ohhhh so it’s calibrated? It’s at 35ppt right?
- Thread Starter
- #332
OP
That means I have a 1.035 or 45 ppt of salinity. How do I get that lower? Because my alk will also be high right?
The way to lower your salinity is to add more fresh RODI water.
Looking through this thread it looks like you mixed all your water in the tank. Is that correct? In future I’d recommend mixing all water in either 5 gallon food grade buckets or a food grade brute trashcan. Then you can test the salinity of your water and make sure it’s correct *before* adding it to your tank.
If your salinity is too high in your tank now, the way to lower it would be to remove some of the salt water and replace it with fresh and test the salinity after you’ve swapped some water. Keep going until you have the salinity right.
Is the picture shown your result? If so, it is around 35 ppt.
if not, it can be lowered slowly by removing salt water and replace with RO/di
- Thread Starter
- #335
OP
Yeah that’s what i’ve been doing rn. Already got it down 1 ppt
. I’ll keep doing that. Technically the alk and everything else should go down with it right?
You can use this calculator to get close on how much water you must remove.
www.hamzasreef.com
Resulting Salinity Calculator
Aquarium calculator; Estimate the resulting change in salinity when water is added, replaced, or evaporated.
www.hamzasreef.com
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