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Phosphate levels....how high is too high?
Badmans Tropical Fish Message Center: Tank
health and maintenance: Phosphate levels....how high is too
January 23, 2002 - 04:45 pm
Hi...I've been fighting a losing battle against an algae
bloom in my 90 gallon tank which started about three weeks
ago following a routine water change. Up until then my tank
had been sparkling clear since I set it up in September,
as had my previous 15 gallon tank which I had had for a
year. After reading a lot of previous posts on this site,
I thought it was caused by a high phosphate level in my
tap water, perhaps because the local waterworks had changed
its procedures. Anyway, I called the water works today and
was told that they had not changed anything and the phosphate
level is ".173 micrograms per liter of orthophosphates."
Is that high enough to cause an algael bloom? My tank has
six rummy nose tetras, nine neons, 3 platies, 3 hatchet
fish, four corys, one dwarf pleco and one golden algae eater.
Since the problem occured I've been keeping my light
on only a few hours a day. When I first turn on the light,
the tank is a little better, but within 2 or 3 hours you
can barely see through the pea soup. My ammonia, nitrate,
nitrite levels are all normal. Help!
January 23, 2002 - 04:47 pm
Also, I have a 404 Fluval Canister filter running with Zeocarb
and Biomax rings.
January 24, 2002 - 07:27 am
You aren't adding any chems with phosphate like ph down?
How often do you change the water and how long did you leave
the lights on before the algae took off?
January 24, 2002 - 09:33 am
No, I'm not using any chemicals. I do a 10-20 percent
water change every 7-10 days. Before the algae bloom, the
lights were on for about ten hours a day. As my husband
says, we seem to be doing everything right...
January 24, 2002 - 11:18 am
tami..regarding your phosphate levels...actually you are
getting close to a problem level of 1ppm..but you are still
OK.. anyway sometimes the things to check are one, the type
of food you are using to feed your fish..it can contain
high phosphate levels so if that is the case switch foods
and ease off a bit on the feeding..or secondly you can use
a phosphate absorbing resin in your filter media..however,
please check your actual phosphate levels in your tank to
be sure, if this is your problem then you can work on fixing
it,however it may not be.. what exactly do you have in that
tank for light and is there and live plants in there?...
so drop that light duration to 8 hrs per day.. see if that
has any effect and we can work on it from there...
January 24, 2002 - 08:09 pm
All Glass strip lite...55 watt flourescent. No live plants.
I've already dropped the light to three or four hours
a day for the last week and by the end of that you literally
cannot see the fish unless they swim past the front of the
tank. I've been looking for a phosphate test kit, but
haven't had any success. I guess I'll try my lfs
to see if they can test it for me. How do I tell if the
food I'm using is high in phosphates? I did start using
a different flake food (Tetramin) right before this
started. Thanks for the help
January 25, 2002 - 11:05 am
tami..green water algea usually means too much light..time
to either completey cover your tank on all sides so it recieves
no light at all for about 4 days or get a diatom filter
and or UV filter..also add more filtration..and if you are
looking for low phosphate fish food it will indicate it
right on the label..