All the fishes in my tank died

[hypnogogia]

The drop checker turned green by the end of photo period.

It needs to be green at the start of the photoperiod and stay green.

 

[maverick786us]

Just 2 days ago I changed the drop checker. I was blue-green when the intensity of CO2 was bit low. I will check it again in 8 hours

 

[Andy Pierce]

It needs to be green at the start of the photoperiod and stay green.

Agree. Since you don't have any livestock in the tank you can be aggressive with the CO2 injection and aim for green/yellow in the drop checker. You won't hurt your plants to have high levels of CO2 (quite the opposite).

 

[maverick786us]

Those are not enough use the below plant!

Hygrophila polysperma - Dwarf Hygrophila

Hygrophila polysperma is a robust and highly adaptable plant originating from India and Bhutan. There is also brown variety native to Sri Lanka, which has been brought into trade by the aquatic plant nursery Tropica and is sold under the na...

www.flowgrow.de

Can you suggest me an alternative. It’s dwarf version isn’t available and the guy from who I buy plants said that it looks like Indian weed which is banned in most of the states