Had planted tank setup for three months.
Read about co2.
Put excel in tank as per bottle said in one day four rainbow died on one capful.
What am I doing wrong or is the directions wrong on the bottle.

Also is this there other co2 dosing better?

What are the parameters of your water chemistry. Difficult to say without knowing.
What type Rainbows ? If nitrites were running high then Excel may have tipped the scale ? Or contributed to a wide PH swing (Given the lighting of your sytem that's unlikely). Too difficult to assess without knowing the parameters of your
system. Prof M

Excel is a good product, but in the end tanked Co2 almost always wins out.

Melanotaenia maccullochi McCulloch's rainbow they were.

Water is
ph - 7.0
kh - 5 dkh
gh - 5 gkh
nitrites - 0
nitrates - 10
ammonia - 0

I keep rainbows and I use a great deal more Excel than you say you do and I have no problems what-so-ever. I very much doubt it's the Excel. Do a 50% water change.

Good luck.

Was there any algae in the tank or excessive algae prior to your dosing the Excel ? Some Cyano Bacteria will release destructive/toxic enzymes after a die off. Some Rainbows are sensitive to Mycobacteria.

Other than that your chemistry looks great. It's a mystery ? Like Russ I've used Excel quite a bit, and even at twice the recommended dosage my Rainbows are fine. HTH. Prof M

Russ, doing weekly 50% changes now for three months.

Professor Myers, Cyano Bacteria I do not see it only green spot.

I retested the water all the same but there are High phosphate levels at 10 ppm will that make it toxic?

When I do the water changes the plants fizz and bubble alot after can you all tell me what that means?

Do you all know of any things else that will be in the water that will make it toxic and what not to add with EXCEL that makes the water toxic so I know?

Tap water etc can change and most of us seldom test it.
Excel many have used and added that same amount with the same species of fish without incident........... so it's very unlikely it's anything to do with the Excel causing that.

Live food/not enough food and many other things can cause a fish death.

Regards,
Tom Barr

Tom Barr,
Thank you for your help I will add it again to the tank per the bottle said.
Now is there a differants in co2 between in a bottle as Excel or is gas better as the yeast gas?

Most tap water tends to be high in Co2, and the alkaline hardness hasn't had a chance to degrade. If you witness "Pearling" predominantly after a water change then chances are you need more Co2 added to the system. Your plants obviously can metabolize more than you have present in the system the rest of the time. This is a neat indicator to give you a bit of insight into the Co2 chemistry of your own system ! Savvy ?

FTR 10 ppm phosphate is not necessarily high ? If you increase the Co2 your plants may make better use of the available nutrients, and lower that a bit ...

Some municipal water treatment experiences an increase in biological activity in periods of temperature tansition (Fall, and Spring fer instance). They usually compensate for this with added chemical treatment. In order to effectively remove those chemicals at the end of the process they may utilize Alum to mechanically filter out those additives. Alum causes many chemicals to congeal like chicken fat. Unfortunately it also causes blood vessels to constrict. Small blood vessels such as you might find in fish or your BRAIN ! may constrict to the point of bursting under blood pressure. Fish suffer massive coronarys. People suffer a high occurence of Strokes, and brain damage in infants (Cerebral Palsy). For a superior species we don't always grasp the big picture ???

So you know I do not have tap water I have a well water.
That is why I asked about why the water changing the plants doing this after as you said call it "Pearling" then if there is something I need to test the water for if it was toxic in the well.
So I know and not ask a dumm question for furture what is the plants doing as pearling!
Thank you for helping me.