Phosguard

tanhql · #1 05-24-2008, 11:37

Can I overtreat a tank with phosguard? Because I use a canister filter for my brackish tank, and I only open it once every six months. I've read that overtreating with phosguard can lead to pH crash, as phosguard can also absorb carbonate. Would that be a problem if I add like half a teaspoon of Seachem Marine Buffer to my daily top-up water (which I am doing right now anyway to maintain the pH at 8.3) to buffer the water? Would Phosguard absorb the carbonate so quickily that even adding Marine Buffer daily cannot maintain the pH? BTW, It's a 20 gallon brackish tank, at SG 1.005. What is the maximum amount of Phosguard would you recommend to use? Thanks.

Edit:
Tank phosphate level: 0.25ppm
Source water Phoaphate level: 0.5ppm

Tech Support EH · #2 05-27-2008, 10:43

Phosguard will remove phosphates and silicates preferentially to anything else that may be in your tank, as it has a specific affinity for these two. Since you do have phosphate in both your tank water and source water, there is no need to worry about carbonates being taken out, or pH fluctuations as a result of using this media. Using Marine Buffer(a very stable buffer) will help keep your pH where it should be, as well.

For a 20 gallon tank, you should probably only be using about 1/4 cup of PhosGuard. There is a question in our FAQ that addresses the quantity issues surrounding PhosGuard:

PhosGuard is best used in smaller quantities and changed frequently. In an environment with an excessively high phosphate reading, PhosGuard will exhaust rapidly (4 – 5 days). Place the product in a high flow rate area and test your phosphate levels, changing as needed. When you see that your level is below 0.2 ppm (mg/L) leave that portion of PhosGuard in the filter. PhosGuard may yellow somewhat as it picks up organics, but that is not an indicator of exhaustion for phosphate removal. Continue to test weekly for phosphate until you see it begin to rise again. You will then know that it is time to change the PhosGuard. If you have low levels of phosphate the PhosGuard will absorb the silicate in your system. It’s inert and safe to leave in your filter.