Goals, reducing labor in a planted tank, and ISE probes and test kits

Tom Barr

Staff member
Jan 23, 2005
Several folks have asked me a bit about NO3 meters
AB use to make a sell a NO3 monitor that had a control function that would automatically change your tank water if the NO3 got to a certain user defined ppm. AM also sells one for marine tanks.

But ISE ion specific probes have many issues.
They are great for measuring many samples at once, and in test vials, but hardly useful for small batches etc or contiunous monitoring.

They have many intereferening ions that make the measurement very difficult. So if you take a sample of water out of the tank, subject it to various chemicals, you can remove this intereference.
But we cannot do that in our tanks continuously unfotunately.

Test kits like Lamotte of Hach also do the same types of things chemically and are read out in color/adsorption units/light transmittenace etc instead of mV's.

So the bottom line is there is really no good way to monitor the levels automatically to reduce the labor of testing for these nutrients.
You can test every 10 minutes, hour, day, week etc to answer certain questions, how much you want to do is up to you and also the question you hope to answer.

So how might we approach things in terms of reducing labor/cost and still monitoring the levels within a good range?

It's rather odd, I started off not testing, then teaching folks to test when I was kid at the LFS, then stopped later for several years and watched the fish and plants, then after seeing success in planted tanks vs other folks, I started testing again to see why and how and if my hypothesis where right/correct. I found it took a lot of work to answer a single question. I flubbed up and had to start over a dozen times in some cases.

Then I realized 99% of folks hate testing and perhaps can never or will never test. So I used the water change idea to suggest EI or go with non CO2 for a slower method. Or less light etc. I have for many years now.

But.............folks do not listen well either

Damn if you, damned if you don't.

I'm at the lab here right now for that matter running N tissue samples.
Yeeha........... Rolling Eyes

The thrill of testing and gobs of data to wade through.........oh yea, I just love waiting, glorified factory work is what I call it.

I would never do this as part of my "hobby", I do it to answer specific questions and hypothesis, not some monitoring routine that makes me do even more work and adds more assumptions into the management of my tanks.


However.........I have enough common sense to automated and semi automate water changes if that's an issue(and it is for me! I'm lazy too).

We do the same types of things at the lab also, we just dribble in water continuously and dose every 1-2 days.
So do most farmers and growers.

Same deal with fish breeders.
So it's helpful for plants and fish.

The higher accuracy does not mean I have less work with a 3000$ unit vs the lamotte test. I tend to have more work to test and set it up.

So we are really not going to get out the labor there.
So rather than monitoring NO3/PO4 etc, we can do water changes which I can automate and as well as dosing of NO3/PO4/Fe etc.

Thus it is easier/more practical, technically feasible, simpler and have less assumptions to automate that(water changes), than to automate testing.

Think about that the goal of reducing labor and cost here.
Which trade off is really easier for you?

ISE probes also ain't cheap, 300-500$ and 200-500$ for the monitor.

It's hardly a simple one size fits all thing.
Some want slow growth, some do not.(less light, non CO2 etc)
Some want to do things very cheap, some don't.
Some do not have grand scaping plans/goals.
Some want high light for whatever reason.
Some do not mine the work, some do.
Some wnat a nice scape and garden often.

I turn a valve to drain my tank, this makes it easier to prune and work on the tank when it's 1/2 full, it gets rid of detritus and keeps it very clean.
If you keep large tanks, you know it's a PITA to get into it when it's 24" deep and 24" front to back. Fish love large water changes and it can allow me more fish loading in the tank with less algae issues. That's why fish breeders do routine large water changes. Breeding, good development of fry and allows them to feed the fish well.

I turn another valve to fill the tank.
I never touch and bucket or a hose.

I never need to monitor any nutrient levels because they can never build up beyond a pre set level based on the weight of the ferts/volume of the tank water.

So no testing and no labor for the water changes.

All I do is prune and garden, clean a filter etc, add more CO2 etc, feed plants/fish which is what folks generally wanna do anyway in the hobby.
So how bout the cleaning of the filters?
Can we, use that grey matter to weasel around doing this chore as well?

I do have an idea for that though: using the wastewater from the water change and two valves, we can back flush our canister or sump type filters to go to the drain waste water, basically looping the drain water through the filters in reserve but not have it go back to the tank, rather, to the drain.

This is not a hard plumbing situation to overcome.

So no filter cleaning, no water change labor, no testing.
Other than pruning, my non CO2 tank gets about the same labor as the CO2 enriched tanks do.

Less work, better results, less assumptions, less barriers in my way to motivate me to keep up on the tank.

Tom Barr