Tap often has PO4.
That's how we discovered why my tanks did so much better with so many plant species, my tap had 1.1-1.2ppm of PO4.
We called up the utility, then measured with a Hach PO4 test kit and a Lamotte test kit.
We should have made a reference solution as well, but did not.
Anyway, Steve's tap has zero PO4, and so he started adding KH2PO4 after seeing my tanks in disbelief.
He could estimate how much PO4 he was adding via mass and volume, no dosing calculators where around back in those days!
Those levels matched with the estimation using the test kits.
So we had some confidence.
As far as heresy, well, it takes over 10-20 years to change things in the hobby.
It's been about 10 years now since folks have been adding PO4, at first most where pretty conservative, as sloppy folks started doing things(about 7years or so ago), we noted that even 1.5-3ppm ranges also had better effects on some plants and on Green spot algae.
So now most go with 2ppm as a range target.
You can add more, but it does no good really.
The best approach to the guys at the LFS's, bring in lots of plants to trade and pretty pictures.
Tell them how is it that you add all this PO4 raw into the tank and why don't you have algae if what they say is really true?
I mean let's be honest, if someone suggest that excess levels of PO4, and just that, nothing else is causing the algae, then we shouild be able to add lots of PO4 and => get algae.
But we do not so how can we believe that hypothesis?
We cannot.
Try it and see.
Tell them to do the same.
Do not guess and assume, that's not any good.
Same deal with a test kit, do not assume and guess they are okay or not, try it and see if they are by using a known amount of PO4.
This is what researchers must do when they take their measurements.
But all the hacks that whine and complain that EI is bad, shot in the dark etc cannot suggest how to calibrate a single test kit, a bit ironic ain't it?
Knowing a little is more dangerous
Sad thing is, many never get beyond just knowing a little.
Look at both sides of this issue, I know it's easier from a management perspective to not test and use water changes to re set the tank. And if I do test, I use the test kits that are the best there are and that I calibrate myself.
That way all that work/labor and $ is not wasted.
I also test intensively when I do test.
It's too much work and labor to test continuously like many folks suggest that you do, but of course they admit later that they do not test unless there's an issue or they only measure one main parameter.
You have to take your own advice, which many do not.
I like to test for most issues in 1-3 week blocks.
I slack off after that unless it's a job where I'm getting paid to do it etc.
1-3 weeks is the typical time it takes to turn a tank around from a bad terrible state to a nice healthy one.
So I can correct things and send them on their merry way in this time frame.
Your tank: CO2, CO2 and CO2.
Trim off any BBA.
The plants will grow back and some CO2 tweaking is all you need from there.
Regards,
Tom Barr