[dogdoc]

I have something going on that I can't quite figure out. My phosphate levels don't jibe with my fert regime. When I dose the straight EI for a 60-80 gal tank. I always end up with really high test levels at the end of the week.

I have tested my tapwater and it registers between 0 and 0.5ppm. I dose KH2P04 at 1/4 tsp three times per week. The tank is heavily planted, pressurized CO2 and I run a TEK 4x55w light (all 4 bulbs only 2 hours a day and 9 hours total.

When I test, my PO4 test is usually off the chart. Do I have a bad test kit. If so, how come my tapwater tests O.K.?

 

[mistergreen]

1. fish poop adds to the phosphate.

2. the plants are missing something, so it's not using the phosphate.

 

[Betowess]

I have read that PO4 tests are notoriously off mark. Same with AP nitrate tests, so folks calibrate them. Mister Green is probably right on. But I thought fish poop made the nitrates and excess food gave the phosphates. Doesn't matter, same thing. Maybe upping the light a little in the midday might help bump up the phosphate uptake too. I know as a TEKster that can be "dangerous" if the tank isn't close to balanced. If you don't have any GSA, you may have enough PO4. Some people dose close to .05 ppm.

 

[dogdoc]

I hope that the plants aren't missing anything. I dose EI macros day 1.3.5. And TMG days 2,4,6 with flourish iron at least twice a week. CO2 is crankin, at least according to the charts it's huge. Don't have a drop checker yet.

I guess what I'm trying to decide is this.... Do I forget the phosphate test and just keep dosing straight EI, or do I take another route?

 

[spypet]

I never dose nitrate or phosphate because my
heavily planted well populated tank produces
enough of those macro's naturally. just dose
micros and traces and you'll be fine.

 

[mistergreen]

I never does macros either, except potassium...

 

[kzr750r1]

I never dose nitrate or phosphate because my
heavily planted well populated tank produces
enough of those macro's naturally. just dose
micros and traces and you'll be fine.

Care to expand on this statement a bit?

 

[mistergreen]

fish waste & basic biological processes will produce enough N & P... And even micros if you're lucky.

 

[dogdoc]

Can I really get away without P? I've thought about this option, but I wonder which would be the worst situation. P of 20 or P of 0.

I did a big H20 change this weekend... about 75%. Measure P afterward and still got a strong 5 ppm.

 

[mistergreen]

look at your plants for what they need... 5 ppm P is a little high but good.

low P will stunt the leaves & and it'll start to die.
too much P will drive down your micronutrients because the plants will take them up too fast.

 

[dogdoc]

Well, I did a little experiment. Decided to dose everything the same last week except P. First thing that I noticed is that I got very little pearling. Plant growth seemed slower too.

So this a.m I did another big water change and dose NPK. Almost all of the plants started pearling immediately.

Makes me think that my Phos test is waaaayyyy off.

Thoughts?

 

[kzr750r1]

You'll need to calibrate it with a known concentration to find out. Otherwise your pissing in the wind trusting it. Your eyes are giving you the most information. Happy plants pearl. But they still grow when they don't, just slower for the most part. :wink:

Any algae issues?

 

[dogdoc]

Yeah I did start to get some green dust when I wasn't dosing the P.

 

[Naja002]

What Substrate are You using?

And

How Long has the tank been setup?

 

[dogdoc]

Tank has been set up for about a year and a half. 100% Eco-complete.

 

[Naja002]

Ok, I was assuming Eco, but no one had gone to the substrate.

Is this a new problem? An old problem? Could it be related to the Eco at all?

 

[kzr750r1]

That is a good point. There were some bad bags of ecco going around about the time you say this tank was set up. It took many WC before the PO4 was dropped to a "normal" level.

 

[dogdoc]

I remember that about the time I set up the tank the whole Eco-complete thing was happening. I double checked the bags and they did not have the white liquid that was reportedly a sign of the bad bags. Even then, I bet I have done at least 70+ 50% water changes in the meantime.

 

[Naja002]

Have You had a Phosphate problem the whole time?

and

What kind of fish, etc are in the tank?

 

[Betowess]

Doc,
For the longest time I was in the don't dose much P and easy on KNO3 camp, as the plants were growing fine with a big fish population. Recently I re-started my 90 gallon with Flourite (switched from AS) and started dosing EI. Now this isn't a mature substrate, but I didn't switch to full EI till a few weeks ago. And wow, a few stunted plants really started growing fast and healthy after I switched to full EI dosing with full water changes...

Every tanks different, but I'm with Sean, just look at the plants. My .02 - keep putting in enough P to almost keep the glass clean.