shake

Would it be a problem if I made batches of Flourish, iron, trace and NPK and mixed them all together( making sure dosing measurements are calculated correctly), instead of dosing individually.

Would any of the chemicals used break down because they have been mixed with another product.

Seachem

We don't generally recommend doing that, but as long as you keep the iron out of the mix you should be OK. The iron will precipitate with the phosphate and fall out of solution.

epicfish

I mix up enough for about two weeks at a time just in case I either mix something wrong, or there are cross-reactions between the products and their stabilizer products. That way, just in case something goes wrong, you don't end up throwing out 10 lbs or 10 liters of something.

Seachem

Let us know how that works out.

Newt

I am assuming you are talking about mixing the ferts directly from the bottle together and not adding them individually to the aquarium during the same dosing activity. Correct?

Seachem

It is not a good idea to mix them all together in a bottle
and then dose, because there could be some chemical
interaction between the mixture and some of the
fertilizers one is looking to add can fall out of solution
and be useless to the plants. However the mixture being
proposed above would work well without the iron or the
phosphate. Supplements can be added individually to the
tank according to your dosing regime.