Hi guys.

I have Phosphates screaming over 10ppm. Its heavily planted and I gravel vac twice a month. I also remove dead leaves ect with weekly 50% H2O changes plus mid week top ups. Tap H2O is 5ppm. My Ferts give me a solution to reach a level of 1ppm, which I dose alternate days It must be coming from my food. I feed flake, colour bits and bloodworms alternately and I'm careful not to overfeed (once daily). The food is usually eaten up within 20-30 seconds, plus with 3BNs 8 Ottos and 5 cories in the 90g I'm sure all the food from the bottom is devoured. Is there a particular brand of food I can use that will help reduce the phosphates. Also should I stop dosing KH2PO4 as I am getting high phosphates from tap water and I would still be getting K from my KNO3? I dont have an algae problem in the tank, but I'm affraid with Phosphates that high I could be prone to a bloom. I would seriously appreciate your advice guys/gals. All responces would be very welcomed

I know this post may be in the wrong spot, but I don't have a CC to buy into the full monty for full access to the site, or else I would

cheers.

ziggy

Before you get too excited, what test methods are you using?
Do you have a recent water report from the supplier?

IME, the cheaper PO4 test kits get really squirrley in the extreme ranges: upper and lower. Some just do not work much at all.
Same with NO3.

As there is no pressing issue, algae etc, I'd just keep an eye on the CO2 and routine maintenance.

The only thing might be a pH shift due to PO4 buffering.

Regards,
Tom Barr

Are you adding CO2 and doing EI? I would definatly stop dosing KH2PO4 if you have tap water at 5ppm anyway, that will probably sort out your high figures. Are you adding K2SO4 as well? If you are you could increase the dose of that, (ask Tom for guidence on that one) to bring the potassium levels up.

Some fish foods do have phosphates in them, although I think theyre getting rarer. It should say on the side of the tub if it has/hasnt.

I wonder though that if your getting good stable growth and no algae problems then it might be worth leaving it be? Tom regularly says that high PO4 on its own hasnt shown to trigger algae blooms, its generally down to some other factor.

Tap water with 5 ppm of phosphate isn't going to be enough to satisfy the plants, unless you do water changes often enough to replenish the phosphates the plants use. A single dose of any of the ferts isn't going to be adequate. If I thought I had high phosphates in my tap water I would skip dosing phosphates for the first after water change dosing only. After that missed dose I would just dose normally. Phosphates in the tap water are just free fertilizer, not something to worry about.

Well, all this assumes that the tap water is 5ppm to begin with.
If so, then a weekly 50% water change means no need to dose PO4.
Just KNO3/Traces, maybe GH

Regards,
Tom Barr

I am having the same problem. Along with a green water problem. Called the water company today. 6ppm average with a range of 6-8pmm out of the tap. Guess no more K2SO4!

Just wanted to say thanks for the info!

First off... Thanks to everyone that responded, all points noted. As far as the water params from the supplier, ya I have 2 week old reports with a confirming 5.2 PO4 ppm. I had them out to my place to test my ammonia levels as they were screaming at 5.5ppm out of the tap. So I'm confident (for now) with the test readings. I use the Hagen master test kit, and I also purchased a digital meter from the water company. I lucked out, the city bought new ones and I managed to buy their old one( 4yrs old) for $175. I'll continue to dose my trace and KNO3 and stop the KH2PO4 .

cheers.

zig

Well, with that nasty tap, you better buy RO, not for the plants, but for you!
What on earth are they doing putting all that NH4 and PO4 in the tap?

I'd be pissed off. I have a water treatment operators' license though.......
Well, this is good news as far confirmation.

So dosing with the tap (please, use the RO for drinking and cooking , washing etc is fine, never give such foul water to kids/infants!):

K2SO4
GH booster(mostly K2SO4)
Dose about 1/2 the KNO3 after water change, then normal on the 3rd and 5th day after the water change.
Traces etc.

That's some nasty tap water.

Regards,
Tom Barr

Ya, it's actually well over American standards, however there is no legislation here concerning NH4. They use some voodoo equation to justify the NH4 and use chloramines as the culprit, which it is, but there is no recourse for the high NH4.
At any rate, I do drink RO but cook with tap. Funny thing is I live in a city of nearly a million folks, one would think the water standards would be a little higher.....

Hi Ziggy, I was just wondering where you live? Cheers, Matt