I've been testing my tanks the past three days straight (doing a week-long daily testing regimen to see how my tanks are doing). Here's my situation on my main (29 gallon) tank:

Today -
pH 6.8 (drop checker is green)
ammonia 0.25 ppm (I'm guessing it's zero since I'm using an old API test kit)
nitrite 0 ppm
nitrate 5 ppm
KH 6 degrees
GH 7 degrees
phosphate 2 ppm

My ten gallon measures the same, save for an elevated pH (7.6) since I'm using less-effective means of injecting CO2.

The phosphates are elevated and are coming from my tap. Is there a natural way of lowering them? I'm not about to go and waste my money on packet after packet of Phos-Zorb or any sort of pet supply store solution. I wouldn't worry about them, except that I've heard RCS don't like elevated phosphates.

Thanks in advance for your thoughts.

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Officially fishless until after the move....tune in later for details!

Plants, plants, and more plants. Is it coming from your substrate? Water changes with RO water occasionally will help. Pretty easy to do with a small tank. I'd get the fastest growing plants I could find and load the tank. 1 or 2 fast growers in there may not be sufficient.

I used to think the same thing for my ammonia test. After my tank was loaded with plants, mostly Wisteria, I never saw .25 again. Now that all of my tanks are loaded, I never see it. I mean loaded though. Another way to see if it is a false positive is to stop feeding for 4-5 days or test your tap with it.

The tank already has a TON of plants. Three 1' tall giant hygros, a tiger lotus with about 15 pads and two on the way, three 1.5' wisteria plants, two 1' crypts, some riccia moss and frogsbit. I'm having to trim weekly or the plants will grow right up out of the water. I'm not worried about the false ammonia reading - I know it's zero, I'm just concerned about the phosphates. They have come down 0.5 ppm over the last three days since my last 33% PWC. I've stopped dosing fertz except nitrates, potassium, and Plantex CSM+B. Could I get away with lowering my PWC to 15%. or would that cause an overdose on my fertz?

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EI? If you are dosing mono-potassium phosphate, cut back a little. Could be an invite for BBA though. Plus, I only see one nutrient hog (Wisteria)....could be more, just not sure.

I'm not dosing monopotassium phosphate - my potassium comes from K2SO4. I have KH2PO4 but I'm not dosing it at all. Just KNO3, K2SO4, and CSM+B.

To the extent of my knowledge, the hygros are hogs as well. At least, they grow as if they are hogs.

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Officially fishless until after the move....tune in later for details!

About the only way I know of reducing the phosphates since its in your tap water would be to use ro or use the phosphate pads. I don't think the plants can take up that much phosphates. High phospates can also cause cynobacteria to start in the tank.

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Definitely seeing the cyano bacteria, if it's a brown fuzzy type of stuff that gets everywhere. Might have to invest in an RO unit...

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Officially fishless until after the move....tune in later for details!

adding organic carbon can remove phosphates. the safest way to do this would be using flourish excel. you could also look up the vodka method and try that. it is most often used in saltwater tanks but works just fine in freshwater.

I'll have to take a look at that. Are there any other ways besides Excel (which is expensive from what I hear) and the vodka method? Where's a good source for the vodka method?

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Officially fishless until after the move....tune in later for details!

Most I know, don't dose K2SO4 anymore. They use gh booster in place of it and only do a once weekly dose. I know Tom Barr stopped recommending it some time back. Potassium is also in KNO3.

How does Excel remove phosphates?

Vodka Dosing by 'Genetics' and 'Stony_Corals' - Reefkeeping.com

i have used sugar in my freshwater tanks for about a year or so now with excellent results. it seems that it really doesn't matter what the source is, just about any carbon that bacteria can metabolize works. i really think its only a matter of time before this becomes popular in the freshwater hobby as well.

I'll look into the GH booster, but my GH is already 7 degrees which if I remember correctly is right on. I'll just stop dosing the K2SO4. Is there another way to add potassium besides K2SO4 and KH2PO4? I dose KNO3, not sure if that's enough potassium though....

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Officially fishless until after the move....tune in later for details!

It looks like the carbon dosing will lower nitrogen levels as well, which I really don't want since mine are nearly zero without dosing the fert.

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Officially fishless until after the move....tune in later for details!

excell removes phosphates in freshwater the same way vodka does in salt water. the long story made short is that it feeds bacteria that convert phosphate and nitrate into a gaseous form, which then dissipates from the tank little by little.

phosphates in your tap water... your best bet might just be that RO unit...

If that is the case, then I have never heard of it being used as a method to control phosphate levels. Planted tank keepers dose with phosphates and Excel.....so these have been working against each other?

I need to contact the SeaChem guy on here and see what he says. Not saying you're wrong, just never heard of it before.

i thought about that when i started realized that i was adding sugar to my tank a while ago. i noticed something however, when i add just phosphate and nitrate, i get bacterial blooms, as one would expect. when i use them together with excel or sugar, i dont, the water is crystal clear. i have also noticed that my faster growing plants dont like excel or sugar.

Well...If you like floating plants...look at Azolla. Loves phosphates.

Thanks! Do you know where I can get any?

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Officially fishless until after the move....tune in later for details!

You can check with a pond supply store. They may be able to track some down. I see people selling it from time to time online.