Why macro doesn't grow?

[euphylius]

My white plastic sump is without separate chambers. Inside are skimmer pump, return pump and heater. I was trying with almost every type of macroalgae, but they donââ"šÂ¬Ã¢"žÂ¢t want grow. Lights are 2 x T5, also tried with compact. Phosphates very low, nitrates undetectable.

I can't find the reason for this. Can heavy aerated water from skimmer inhibit macro to grow?

 

[sunfishh]

How deep is your sump and how many watts are your t5's?

 

[euphylius]

2 x Osram FQ 24W 860, sump 38x50 centimeters. Water 16 cm deep.

Regards.

 

[graveyardworm]

You answered your own question.

nitrates undetectable

 

[euphylius]

Tnx, but I thought that many reefers with undetectable nitrates have full of macros in sump.

 

[graveyardworm]

The reason for the undetectable nitrates in their tanks could very well be because of the macro. If you have no nitrates to begin with, and you arent feeding regularly enough the macro can consume enough to run out and starve and thats when you hear stories about caulerpa going sexual and polluting the tank. I have 2.5ppm NO3 now and I have poor macro growth so I'm going to start nitrate dosing and see what happens. Also a lack of iron can result in poor macro growth, but if you dont have alot of macro regular water changes may be enough to replenish trace elements like iron.


What spectrum are your lights? 10,000k, actinic ?

 

[euphylius]

What spectrum are your lights? 10,000k, actinic ? [/B]

No, as I wrote they are type 860, 6000K. Are you keeping SPS?

 

[graveyardworm]

<a href=showthread.php?s=&postid=6880254#post6880254 target=_blank>Originally posted</a> by euphylius
2 x Osram FQ 24W 860, sump 38x50 centimeters. Water 16 cm deep.

Regards.

Sorry this post didnt indicate 6000k, and I dont know what the osram 860 is, but thats the info I was looking for. So the light spectrum is correct. I would go back to nutrients , and say that your system being as low on nutrients as it is seems to be not enough for rapid growth of macro. Try feeding the fish a little more if you have fish. Otherwise if you want really good macro growth you may have to look into dosing.

Sadly I lost most of my SPS during a dinoflagellate outbreak about 6 months ago, and since I was setting up a new system I havent raplaced any yet.

 

[The_Nexis_One]

I completely 'second' Graveyardworm's conclusions.

John.