I think I almost killed my HC

[Fishnut]

I put it in with my amanos for a cleaning...just in case.  It was doing great.  When I moved it into it's new home with that Red Sea gravel like stuff as a substrate, it started to die off.  The light, I know, wasn't the right light.  I think it was way too low.  Now the light has been changed to a double T5 fixture with a 6700K bulb and a 10,000K bulb.  I'm leaving it on longer than I really should because of the dieing HC.

What I would like to know is should I add fertilizer or CO2 to help it start growing back or just wait for the light to help it?  I don't really want to continuing either ferts or CO2 once the HC has come back but the bio load in the tank is quite small.  It has the CPD's and a few shrimp in it.

What should I do??!!

[Consigliere]

Ferts and CO2 will both help unless all the plants have completely died.  No brainer to try it.

[charlie]

The roots might still be in good shape, adding co2 & nutrients will surely help it , another option is to try growing it emerged until it really takes off, i know jetstream & fischkopp have done this successfully.

[fischkopp]

I tend to say that CO2 is a must have if you are growing HC submersed. Fertilization shouldn't be necessary in the beginning when using an nutrient enriched substrate.

The emersed growth in black soil (cover well for humidity) is great to recover HC, I always keep some backup outside the tank.

[leng]

<snip>
What should I do??!!

If you mean HC cuba....they grow well when flourish excel is added but you do need CO2 injection.  I add the recommended amount of flourish excel once a week after my weekly water change and they grow steadily.

[Fishnut]

Thanks!  I'll give the ferts and CO2 a try.  Hopefully there is enough left to salvage.

[blizzack1]

Thanks!  I'll give the ferts and CO2 a try.  Hopefully there is enough left to salvage.

I tried growing mine emersed and it almost died (shriveling up/turning brown)

I flooded the tank and fired up the pressurized co2, and was dosing about once per week and added loads of excel (not sure if this helped or not) and lots of circulation.

I had 2 x 39 t5HO lights like you and after about a week it took off like crazy and will be a full carpet soon of bright green.