I'm dosing 10 ml per day on a 65 gallon tank, and not seeing any problems. I was dosing half of that for a few weeks, but increased it to see if that would improve the plant growth. It has, but not by much.
When API started selling their Excel equivalent they did testing to show how much better it was than Excel. But, the only real difference was that they tested it with Vals, and didn't do the 5 ml per 10 gallons starting dose, which seemed to stunt the Vals with Excel. That convinced me that it is much better to dose the 1 ml per 10 gallons, and dose every day.
I may increase my dosage to 15 ml per day soon. I use low to low medium light so algae isn't a big problem in any case, as long as I manage to do tank maintenance as I should.
Could it be that Excel isn't the cause for my shrimp deaths then?
I have hard water ,GH-15 ,KH 10.High TDS also.The shrimp were multiplying fine until I started dosing Fe+traces also containing some K.It contained Cu ,also ,maybe it got cumulated in the water?Or the ferts I am dosing at the moment(P and K) from seachem ,make the water even heavier?
I did small water changes for a period of time ,and wasn't dosing the whole range of ferts ,only the micros - I have 20 ppm NO3 in my tapwater ,and I thought enough PO4 was produced by food and excrements at that time.
I used DIY Co2 ,not in the proper way ,also kept light too close ,so I think some kind of deficiency must have appeared ,and the fluctuating Co2 triggered algae -plants didn't adsorb Fe+traces and it charged the water even more.
When I first started dosing Excel ,I didn't realise I was dosing for only 6.5 gal water column ,I dosed 1ml ,as per 10 gallons -full tank capacity.After which ,less shrimp ,a few deaths here and there ,even the Amanos went in hiding ,and huddling eachother ,sometimes twitching their flippers ,as shrimp do when they are berried.The amanos still live ,but I don't see that many Red Cherry anymore.Now I dose 0.5-0.6 ml every other day.
In the end ,I am not sure if I should continue with Excel ,to increase the dosage ,or dose the actual quantity daily.If dose every other day ,isn't that similar to actual Co2 fluctuating?Maybe I'm making it worse?