[maverick2402]

I just did a 50 % water change this morning on my 20gal. and started dosing with Greg Watson's ferts.I tested the water just for the heck of it a few hours after dosing and the nitrates and phosphate are through the roof at about 80ppm and my phoshphate level is at 5.0 .I know I have to adjust dosing the new ferts and was wondering if I should change somemore of the water to get the nitrates down or let the plants take it out.I just started dosing the KNO3,K2SO4,and KH2PO4.
this is how much I am dosing :
1/4Tsp-KN03 3x a week
1/16+Tsp-KH2P04 3x aweek
1/16+Tsp K2S04 3x a week
5ml Trace
1-2ml Fe/Iron

 

[Sorenweis]

Check your incoming water (tap). I think my water company added phosphates without telling me and I had about 40ppm phospates in my tank. Damn them, my plants took a hit, nothing died, most stunted. I also start with 20ppm nitrate as well. How can this be you ask? Yes it is above safe drinking water standards, but my water company doesn't care. Check your tap water first.

 

[John S]

sorenweis 40ppm phospates ????? are u sure u didnt mean 4 ppm i dont think ive seen a test kit that reads anything above 5 ppm phoshates is that from the water companys report or your testing???? also check the test kit u are useing most of them arent very good

 

[g8wayg8r]

Chuck's Aquarium Page

Go to this site and get the calculator. You're adding over 2.9 mg/L of phosphate every time you dose. That's 8.6 mg/L every week. With a 50% water change you will eventually saturate at 17.2 mg/L. Even if your plants use some phosphate, that's still a lot.

If I were you, I'd do a few water change and start calculating what you're dosing.

 

[Georgiadawgger]

Check your incoming water (tap). I think my water company added phosphates without telling me and I had about 40ppm phospates in my tank. Damn them, my plants took a hit, nothing died, most stunted. I also start with 20ppm nitrate as well. How can this be you ask? Yes it is above safe drinking water standards, but my water company doesn't care. Check your tap water first.

If its above the MCLs...contact your regional EPA office (region 3) and provide the details...it will get fixed. Also contact your state and county water board in writing.

 

[eds]

Sounds like you dosed a little too much.
You could do a partial H2O change, but I don't think your levels are so high that you'll damage anything.
If the levels don't drop over the next few days, something else is wrong with your tank.
I'd probably just skip the next macro dosing - or maybe the next 2.
And then when you resume, dose no more than 1/2 what you dosed before.

Just curious - in addition to your tap water, did you do NO3/PO4 tests before the H2O change?

 

[maverick2402]

I tested the nitrates 2 days prior to the water change and it was at about 10ppm.Stupid me,I didn't test the PO4 before the change.For all I know the PO4 could have been high from the get go.I just bought the PO4 test kit a few days ago.I think your right in just riding it out for the next couple of days and skip a dosing or 2 if needed.

 

[bastalker]

How about filling a glass with tap water, an testing the P04 after it sits for 24hours, an see what ya get. Ya might find out ya have free ferts...

Do you have alot of plants in the tank to suck up the ferts?

I dose my 55G with 1/4 tsp of KN03 3 times a week, an I maintain 10 ppm. You might be over dosing N an P a little bit.

 

[maverick2402]

How about filling a glass with tap water, an testing the P04 after it sits for 24hours, an see what ya get. Ya might find out ya have free ferts...

Do you have alot of plants in the tank to suck up the ferts?

I dose my 55G with 1/4 tsp of KN03 3 times a week, an I maintain 10 ppm. You might be over dosing N an P a little bit.

I tested the PO4 right out of the tap and it was .5 ,so I'll try like you said and wait 24 hrs.I just did a 50 % water change a couple of hours ago so I'm going to test the tank to see what I have after the change.Yea I think I over did it a little in the beginning of the week when I dosed it for the first time ( I'm still getting used to the new ferts).I think I'll start out dosing very little if it shows that it needs ferts when I test it .I have about half the tank planted with stems and cork screw vals.,some red temples and a bunch of other plants.

 

[Sorenweis]

John S,
sorry to get back so late, but I figured at or above 40mg/l since it was off the test kit charts and after I did a 90% water change it went down to about 5mg/l. I tested out of the tap when i did the water change and it read pretty much 0.

I have three tank and all get different food and whatnot, but all had off the wall phosphates. I can only assume that it came from the tap water one day, I hadn't changed anything in my routine for months and the water always checked out fine. I get the idea that the water company does whatever it wants as long as they are in comapliance with the EPA and FDA. Even then, our nitrates are consistently too high.