Gotta Get a Handle On This

[imatrout]

I have an issue that is driving me CRAZY. I keep measuring PO4 in my tank at 30 PPM. I actually think its much higher, but I can't accurately dilute my test further. I use a Salifert kit that requires 10 ml of water. When I test I use 1 ml of tank water and 9 ml of distilled water and I still get a reading that apears close to the color of 3.00 ppm (max) on the color chart. I multiply that by 10 and get 30 ppm!

I quit adding KH2PO4 4 water changes ago and the readings have not changed. The plants are pearling and look healthy and the only algae I get is a few wisps of thread and as couple of spots of GSA (go figure, I thought GSA was caused by LOW PO4) Other params are: GH 15, KH 8.5, NO3 15-25, PH tap, 8.0, PH with CO2 6.7.

This is a 150 gal tank with a very low fish load. It houses 8, 5" discus, 2 rainbowfish and 6 corys. That's it! I do feed the discus very small amounts of freeze dried bloodworms and flake 3 time pwer day via a feeder and I feed frozen bloodworms every evening. I hand feed them to ensure they are thoroughly consumed.

I did recently added a poly bead fluid bed type filter, and Ocean Clear 354.

http://www.aquadirect.com/store/cat...bead_Mechanical__Biological_Filter_p_327.html

Could this unit be a phosphate factory?

I am really at a loss as to what is causing the PO4. I do have an Eco-Complete substrate and I know it had a problem with a buffer additive that caused high PO4 readings, but shouldn't that have rinsed out over 15 - 20 50% water changes?

Any ideas would be very appreciated. This is driving me crazy. Also, the Salifert test kit gives you a reading for phosphate and another reading for phosphate-phosphorous if you divide the results by 3. What does this mean and does it have any bearing on the situation? Just so you know I have used 4 different test kits to confirm reading

 

[alexperez]

Re: Gotta Get a Handle On This

And all 4 kits could be wrong. Make a reference solution of PO4 to validate the kits.
Could there could be something in the water that is throwing the kits of?

 

[imatrout]

Re: Gotta Get a Handle On This

And all 4 kits could be wrong. Make a reference solution of PO4 to validate the kits.
Could there could be something in the water that is throwing the kits of?

Like what Alex? I add nothing to the water other than ferts. I only use Dechlor when I change more than 50% of the water. Other than that, I am adding nothing.

 

[alexperez]

Re: Gotta Get a Handle On This

Maybe something in your tap water changed?.

If not then I would still check your test kits.
I say this because of my experience with test kits.
Red Sea,AP,Seachem PO4 kits Kits said one thing.
And when I finally got the lamotte kit it said another.
So eithier the Lamotte was wrong and the others where
right ot vice versa. I'll put my money on the Lamotte kit.

Also you say this.

I quit adding KH2PO4 4 water changes ago and the readings have not changed.

This should have caused your PO4 levels to drop so the only 2 things that I can think off is something in your tap water changed or the kits are bad.

I'm just throwing ideas your way. I know how fustrating it can be trying to figure out some of the problems we come up against in this hobby.

Alex

 

[imatrout]

Re: Gotta Get a Handle On This

I have used 2 Salifert kits, an AP kit and a Red Sea Kit. All vary, but all read higher than the base test limits. My tap water has zero detectable PO4.

I am going to make a reference solution using distilled water and KH2PO4 and see if it agrees with the test kits. Something is amiss and I appreciate your ideas a lot!

 

[PK1]

Re: Gotta Get a Handle On This

Don't rule out a bad batch of Eco-Complete. 15-20 water changes may not be enough if it is indeed the Eco.

You may want to give them a call, I had an issue and found them quite helpful.

 

[Cornhusker]

Re: Gotta Get a Handle On This

imatrout,these test kits can be our worst enemy at times. i use lamotte and they can leave a lot to be desired.if a situation such as yours gets out of hand i would send sample of water to a lab in your area.this is the only way to know for sure what is going on.ask them for other data too,like kh,gh,nitrates and so on so you get your moneys worth.i think about the only test kit out there that is any where accurate would be an ammonia test.i went to my soft water dealer in my area for a sample bottle and proper instructions. these are usually free for the asking. regards,cornhusker

 

[imatrout]

Re: Gotta Get a Handle On This

Great idea Husker. I think I'll do exactly that. At least I'll know for sure. I'll do all my own tests at the same time and get some calibration on all my test kits.

Thanks!

 

[Cornhusker]

Re: Gotta Get a Handle On This

imatrout, i think the cost on my tap water testing was $27.00 with return shipping.it would be interesting if they could test the co2 content,but i don't know if that would presipatate by the time they got the sample.good luck! regards,cornhusker