Today we are going to take a look at how to use the Hanna Phosphate checkers along with GFO to monitor and control and phosphate levels in your tank.
There are a number of test kits on the market that will let you check on your phosphate levels but some of our favorites are the Hanna Instruments Phosphate checkers. Hanna offers two different checkers: the Low Range Phosphate and the Marine Ultra Low Range Phosphate Colorimeter, both of which operate similarly and are easy to use. These will let you know exactly what kind of phosphate levels you are dealing with. Check out our video on phosphates that we linked below to get a better idea of what these levels can indicate.The standard Low Range Phosphate checker will be more than enough for most aquarists. It measures phosphates levels between 0.00 ppm and 2.50 ppm with a resolution of .01 ppm and a accuracy of +- 0.04 ppm. The Ultra Low Range checker measures levels between .00 ppm to .090 ppm with a resolution of .001 ppm and a accuracy of +-0.02 ppm. The Ultra Low Range checker, having a smaller window of measurement and a higher degree of accuracy means that the ULR checker will be better for those really trying to draw a bead on their phosphates and get their levels down to zero.
Using the Hanna Phosphate checker is pretty simple. The first step is to turn the checker on by pressing the center button. Once the screen is flashing “Add, C1” you are ready to get testing. Fill the cuvette 10 ml of water from your tank, and place it in the checker and close it. Press the button and wait until the screen reads “Add C2.” Remove the cuvette, add the appropriate reagent to it, and shake it for two minutes. Once all the powder is dissolved, place the cuvette back into the checker and hold the button until a timer appears on the display. Once the timer runs down, your phosphate level will be displayed. The only difference in using the standard phosphate checker verses Phosphorus ULR is that each checker has its own reagent to add to the water during testing.
One of the most common ways to deal with phosphate issues is to use GFO. GFO or granular ferric oxide will bind the phosphates in your water to it as they pass through. Because of this, the GFO needs to have sufficient water flow. There are a couple ways that you can achieve the necessary flow in your system. The easiest way is to simply fill a filter media bag with it and place the bag in a high flow area of your sump or filter. Keep in mind that water takes the path of least resistance, so since you aren’t actively channeling the water through the GFO, its going to be a bit less effective at absorbing your phosphates. Also remember that GFO tends to have fairly small grains, so it is important to put it into a media bag with a small enough mesh size to prevent it from spreading through your tank.
The second way to effectively employ GFO is through the use of a media reactor. For this method we will need a basic media reactor, a feed pump, some tubing, and it is usually a good idea to keep a ball valve on hand as well. First things first, we need to open up the reactor and remove the top sponge, Next we just fill the reactor with the appropriate amount of GFO and replace the top sponge and lid. GFO can have different filtration capacities depending on the quality of it and different size tanks will certainly require different volumes for it to be utilized safely and effectively. To figure out exactly how much GFO you need to use, the best practice is to simply follow the instructions on the specific GFO you are using; however, we do have a calculator on our site which we will link below to help you.
Once your reactor is back together, attach your tubing to your inlet and outlets. In terms of pumps, the required flow rate again will vary depending on your system. If your pump is too strong, you can grind the GFO down on itself and it can blow out of the reactor and into your tank. If you pump isn’t strong enough, the GFO wont move enough and it will fuse to itself overtime, creating a solid block. What we really need to be aiming for is a slow sort of simmer, where you can see most if not all the GFO moving slowly and gently, just enough so that it doesn’t fuse. I will usually try to get a pump that may be just slightly stronger than what I think i might need, and tune it down to the desired rate using a ball valve.
Hanna Phosphate Checkers: https://mdshop.us/HannaPhosphateCheckers
GFO / Phosphate Removal Media: https://mdshop.us/PhosphateRemovalMedia
GFO Media Calculator: https://mdshop.us/GFO-Calculator
How to Lower Phosphate Video: https://youtu.be/fd55peZgBCE
GFO Media Reactors: https://mdshop.us/Media-Reactors
Use Hanna Checkers to Dial-In 2-Part Dosing Video: https://youtu.be/z7jgm6HMyzA