plantbrain

pH's of all aquatic wetland soils tend to be neutral or start off low/high and over the course of a few days to weeks, they go towards pH 7.

If you add more OM(organic material, peat, mulm etc)), they will remain lower(and a lower Redox). Non CO2 systems are ideal for this and this also keeps the nutrients in the soil rather than being oxidized and used up very fast.

If you add less OM, the pH will be neutral and higher redox.

I do think good test kits are sujected to testing errors when the tank recieves no water changes since the organic fractions build up and influence the test kits.

While using a standard is useful if the water is changed often for a reference, adding the natural organic components does influence kits and the what is truly available for plant uptake.

The other potential issue is the low levels of other nutrients/KH, this organic fraction will be a much larger ratio relative to these nutients. I do not know how that may influence things.

I will not even discuss trace testing which I have never found to be of any real use in planted tanks. See Roger Miller's and I's disscussion on the APD, and that was just Fe.

Regards,
Tom Barr

shalu

I suspect I have seen the buildup of organic material affecting test kit in my tank as Tom described. I have a VERY heavily stocked planted discus tank(100gallon), into which I dump more than 3 ounces of frozen blood worms a day. It is the NO3 test(AP kit) in my case. I was changing 50% water weekly for a while. Normally the NO3 test sample should be a clear yellow after the first reagent is added. But I was getting an orange color, it was like I already got significant NO3 reading BEFORE the second reagent was even added! Actually the color became lighter with the second reagent added, and what is interesting is, the final reading took much longer to reach than usual. I took another look at the sample the next day, the reading was much higher than it was 30 minutes after the test. BTW, my AP phosphate kit is toally junk, reagent probably expired from the beginning. It gives me a totally different color than the chart range!

I have increased W/C to 3x60% weekly to keep DOC and nitrate in check. That's what I pay for wanting so many fish. So my tank is reset very frequently(3/week) with Tom's method. The plants are doing very well and there is little algae. It is a little surprising considering I have ample supply of NH4 from fish which should favor algae, maybe my wet/dry filter helps, Tom?

plantbrain

You need to do 2x a week water changes, 60-70% etc.
You'll also need to do K2SO4 dosing in place of KNO3 top offs.
A good filter(or two) will also help.

Why not feed less, give the fish more room?
That's the sane solution.

A w/d filter will convert the NO3 faster, but at some point it's simply not enough, no matter how good the filter is, the algae will still have enogh to grow.

Doesn't sound like you at this point, try backing off the food.

2x a week or 3x a week routine and dosing thereafter.

You will surely want to make very certain your CO2 levels if you get a w/d.

I've seen some well packed Discus tanks that do well, 2-3w/gal, lots of plants etc, minimal overflow splashing!

Also, he had automatic water changing set up 2x a week as well.

Might be worth looking into as a longer term solution to our feeble forgetful minds.

I do not think that this is what Edward had in mind with this thread though



Regards,
Tom Barr

shalu

Sorry, did not mean to hijack this thread. I was just trying to comment on the test kit problem with organic material. Tom, I do not dose NO3, but do reset with K2SO4,PO4, trace with each water change. My method is basically Barr method with heavy fish load(more than enough NO3). I was just surpirsed that my tank is doing so well with very little algae although NH4 supply is high. Love my wet/dry, don't think I lose too much CO2 with it. I keep CO2 at 30ppm per Tom's suggestion

Edward

How to make organic N or P with zero inorganic content for experimental testing?

Thank you,
Edward

plantbrain

You remove the inorganic fraction.

Regards,
Tom Barr

Edward

Tom,

do eggshells and coral contain organic compounds?

Thank you,
Edward

plantbrain

Coral is CaCO3 so nope, eggshells-not sure, doesn't seem like it.
OM can influence Ca/CO3 based compounds.
Fresh activated carbon will also remove dissolved organics and complexes a fair amount.
I prefer water changes and nice set up for easy water changes(open a valve for draining, close it and open another for filling).
Others use a slow drip automatic water changer like Alan and Bob do in our group. Changes 2x a week about 40% at night automatically.
All they do is dose, prune, never touch a bucket or turn a valve.
If you added a dosing pump, then all you'd do would be prune and clean filters.

Regards,
Tom Barr