Tested for P.

jcali10 · Post by **jcali10** » Mon Feb 18, 2008 2:00 pm

I did PWCs yesterday, and then tested water parameters in both tanks and noticed P was way higher than normal. I'm in the Catonsville area. I didn't realize until yesterday that tap water could be so rich in phosphates.

Is this common? When I tested this morning for P, it was back down in the 1.0 - 2.0 ppm range.

Jeff120 · Post by **Jeff120** » Mon Feb 18, 2008 5:27 pm

What test kit are you using? Some test kits arent very reliable. Im sure we are on the same water supply, Im in Ellicott City and havent noticed any change.

John G · Post by **John G** » Mon Feb 18, 2008 6:26 pm

It is certainly common in Fairfax County water.

jcali10 · Post by **jcali10** » Mon Feb 18, 2008 6:36 pm

I'm pretty sure I have the Aquarium Pharmacuticals brand; it comes with 2 bottles of reagent and placards for salt and fresh water.

I was thinking the lower readings this morning could be attributed to the nutrient uptake of the plants.

SCMurphy · Post by **SCMurphy** » Tue Feb 19, 2008 10:31 am

It depends how much farm land is in the watershed where your water comes from. I have a friend in Fredrick County (MD) and if he did a waterchange after a heavy rainstorm his saltwater system would go crazy. He got a RODI system after I pointed this out to him and he hasn't had a problem with excess P since.

DelawareJim · Post by **DelawareJim** » Tue Feb 19, 2008 10:48 am

Nitrogen can be the same way. I'm surrounded by farmland and my nitrates are off the chart. It kinda freaks me out when the test says "add the reagent, shake for 30 seconds and compare the colour after 3 minutes", and my sample is the darkest blue possible as soon as the reagent hits the sample.

I've thought about titrating to see just what the real concentration is, but I don't want to know that I'll be using one reagent scoop per litre of sample water.

Cheers.
Jim

Post by **krisw** » Tue Feb 19, 2008 10:54 am

Jim, so do you not have to dose macros at all?

RTRJR · Post by **RTRJR** » Tue Feb 19, 2008 11:48 am

I'm Frederick county also. For a long time our water was nitrate and phosphate-free (community water system, deep old-water sources). A few years back, the system went public and added another well from the valley. I was terrified, as they said that we would have positive nitrate. It turns out that nitrate is usually 1-2ppm and no issue at all. Folks in the valley below us don't always get that low.

jcali10 · Post by **jcali10** » Tue Feb 19, 2008 1:39 pm

I'm going to continue testing for a while, just to make sure I don't over fertilize.

Rick Dotson · Post by **Rick Dotson** » Wed Feb 20, 2008 1:38 pm

I have decided to grow whatever will live in whatever comes out of my tap. I used to try to change it but got tired of all the mixing, RO/DI and testing.

If it dies I don't bother with it for a while.

Tested for P.

Tested for P.

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