Let's talk about bio load.

[Aquattro]

Originally Posted by SoloSK71

Dissolved oxygen, actual vs. ideal/theoretical

Charles

Near impossible for a hobbyist to measure, but that might do it. Perhaps redox values instead?

[Proteus]

I've though about monitoring orp but after all the research I've done its about as important as ph

[Samw]

Originally Posted by Aquattro

Near impossible for a hobbyist to measure, but that might do it. Perhaps redox values instead?

Why is dissolved oxygen impossible to measure? There are dissolved oxygen meters. I have one.

[Aquattro]

Originally Posted by Samw

Why is dissolved oxygen impossible to measure? There are dissolved oxygen meters. I have one.

Meters are rare items owned by hobbyists. And titration kits don't work well at all.
Not impossible, but not something that is useful, therefore difficult to justify a meter.
Hobbyist meters are also likely not maintained well, so the value could be way off.

[Samw]

Originally Posted by Aquattro

Meters are rare items owned by hobbyists. And titration kits don't work well at all.
Not impossible, but not something that is useful, therefore difficult to justify a meter.
Hobbyist meters are also likely not maintained well, so the value could be way off.

It was useful for me to determine that my tank was overstocked with low DO at night. Without heavy aeration turned on at night, my DO levels were lethal to oxygen demanding fish whereas another reefer who borrowed my meter had a lightly stocked reef where the DO hardly dropped at night. Even with aeration at night my DO was low due to the high bioload.

Here's an affordable one
http://www.amazon.com/Milwaukee-Econ...JCANWD2MRRMSER

[Aquattro]

Originally Posted by Samw

Here's an affordable one

Still $150 bucks! I know so many people that won't splurge on a new refractometer for $40 And that's bit more useful

[Samw]

Originally Posted by Aquattro

Still $150 bucks! I know so many people that won't splurge on a new refractometer for $40 And that's bit more useful

Ok, but if you had one, it can help you determine whether your bioload is too high.

[Aquattro]

Originally Posted by Samw

Ok, but if you had one, it can help you determine whether your bioload is too high.

Ok, I'll give you that

However, that doesn't really address the question.

Skimmer x is good for 200g @ light load, 150g @ med load, 100g high load. How does one determine if skimmer x is appropriate for their 120g tank?

Personally, I've been doing this a couple years now, I just know. I know my bio load, pretty comfortable guessing bio load capacity, and I'm confident in my abilities to size a skimmer.
But for most consumers new to the hobby, what does that mean? Does skimmer x meet my needs? Or do I need x +/-1 for my tank? Generally bigger is better, but if I go too large, I may not have enough load to get proper foam development.

All theoretical discussion with no real answer, just something to kick around.