Hair Algae and Bulb Change

[gigi4539]

I recentley changed my metal halide from a 20 k to 14 k and have had a green algae bloom. My phosphate levels are at .1 Nitrate levels .5

Any one know if this can cause a bloom from the different spectrum?????

[capn_hylinur]

If you had the other bulb for a while and then changed it with the new one--then I could see that more of a problem then going from 20k to 14k.
.5 nitrate reading is going to be definetly a factor---IMO a new bulb and nutrients available will cause the bloom.

[CapitalO]

Most nuisance algae likes light towards the red side of the spectrum (away from blue). This is the reason people associate algae blooms with old bulbs. The new bulb your using might cader better to nuisance algae and help them use the nutrients more effectively since it is a lower color temp. and probably more red sided in spectrum than your previous bulb.

[capn_hylinur]

Originally posted by CapitalO
Most nuisance algae likes light towards the red side of the spectrum (away from blue). This is the reason people associate algae blooms with old bulbs. The new bulb your using might cader better to nuisance algae and help them use the nutrients more effectively since it is a lower color temp. and probably more red sided in spectrum than your previous bulb.

it did not know that---thank you

[rigleautomotive]

some different species of algae prefer different spectrum and intensity of light and i think that would explain the bloom.the nutrients were probably there before also but the algae that prefered that spectrum was spent,now the new takes over and the cycle continues.

[gigi4539]

Thanks! I ordered a new 20 k xm