Yes I forgot to add I am dosing 5 ppm MgSO4 after the water change.
Is that 5ppm MgSO4, or 5ppm Mg resulting from dosing MgSO4? 5ppm Mg should be fine, but 5ppm MgSO4 would only contain about 1ppm Mg which wouldn't be enough.
You could always try increasing the Mg dose to 10ppm Mg just to see if it changes the chlorosis.
Maybe I can try dosing right when the lights begin to ramp. The pH does drop 0.8 - 0.9 by this time. I currently turn the CO2 30 minutes before the lights start ramping and the lights ramp up to full brightness in 30 minutes.
You really want the pH drop to have completed before the lights come on, so if you set your CO2 to come on half an hour earlier it would also give you chance to distribute the micros in darkness. It might not make any difference, but might just be enough to get some iron to the plants.
I'm not sure how long it takes chelates to degrade in either light or pH beyond their range, perhaps
@dw1305 or
@X3NiTH know
Thats a good idea I'm going to try splitting the dose in 5.
I'd split it in 7 if you can - if you are adding it manually, I'd consider an auto doser - it takes the effort out of it a little.
I've been put off from using it on my personal tank from the color tint I hear it causes.
I've not used it myself, but it does apparently give some tint to the water, but I wouldn't suggest that's the only iron source you dose, I'd maybe just use it as a small proportion of the total to give some extra iron availability through the photo period - in which case the tint effect should be more minimal.
I'm going to try splitting the micros in 5 and doubling the DTPA and gluconate dose to see if that helps.
That's worth trying too - though I would try daily dosing for a week before increasing it - I wouldn't normally suggest going above 0.5ppm in total for Fe, but we may need to assume that a lot of the EDTA is being affected by the pH. If anything I'd be inclined to increase the CSM+B dose in case it is an Mn deficiency issue. It is a shame you can't get CSM+B without iron included, or with DTPA chelated iron instead of EDTA, as that would be ideal.