October 1997

Q. Could you please answer two questions for me. I have a 45 gallon
saltwater tank with Amiracle Wet Dry and Marineland Canister filter.
I also have a protein skimmer. First my live rock is a nice shade of
purple and has some mushroom anenomes growing off it. It seems to be
slowly dying. All my levels are low and I change 8 gallons of water
every two weeks. The fish are fine?? What could be wrong? Secondly, I
get algae, looks like hair, growing on the substrate on the bottom
and some of the dead corals. This algae seems to grow like mad for
2-3 weeks then die off. Then it starts again 1-2 months later. Any
ideas??

Rich Williams,
via the Internet

Rich I would love to answer your questions and help you out with your
problems but you have not given much information to go on so I can
only offer you my "guesses" as to what may be the problem. I am not
sure what you are referring to when you say "it is dying" do you mean
the coralline algae, the mushroom anemones or the life on the rock? I
will assume you are talking about the coralline algae. Coralline
algae rely on a number of factors to grow well. Number one is water
chemistry, specifically calcium, alkalinity and pH. Since you did not
provide me with any of this information I can only speculate as to
what may be happening. I suggest checking these levels, particularly
the alkalinity, which should be above 8 dKH and preferably closer to
12 dKH. Unless coralline algae have sufficient calcium, bicarbonates
and carbonates in the system to calcify they will not do well. Other
factors include high phosphates that impede the calcification process
in coralline algae. Phosphates should be lower than 0.2 ppm.
Strontium chloride additions also appear beneficial for coralline
algae growth. There are many different species of coralline algae,
some are found in shaded areas while others thrive on high light
levels. However, since you provide no information about your lighting
system I can not advise you if your lighting is too bright or too dim
for the coralline to do well.

Your experiences with hair algae indicate that there is a slow build-
up of nutrients in the system. The algae will proliferate when these
levels have increased to a certain point. Once they have lowered the
nutrient level enough the algae starve and die-off. The nutrients
then accumulate again and the cycle repeats itself. Check your
top-off water and the water you use to make your seawater with. Make
sure this water is low in phosphate and nitrate. Examine how much you
feed your animals, make sure you are not overfeeding the tank. I
would also suggest removing the biomedia from your trickle filter,
you don't need it and it only contributes nitrates to your system. At
the same time I would investigate how efficient your protein skimmer
is and if you can't upgrade it to a more efficient model.

Regular readers of this column already know this but I will repeat it
once again; when writing to me with problems I need as much
information as possible about the system and how you maintain it.
Without this information I am left to second guess what the reader
means and what may be causing their problems.

Q. I have a 55 gal. salt water reef tank and run a Whisper wet-dry
filter and an undergravel filter, a wave maker with two Maxi-Jet l000
power heads, two 110 VHO watt lights, one white, one blue (bulbs are
one month old) and the temperature is 75 oF. I add calcium, iodine,
strontium & invertebrate smorgasbord weekly as designated on bottles.
I do monthly 10% to 15% water changes and add Biozyme and Marine
Buffer at that time. In the tank is approximately two inches of
crushed coral, live rock, one Sebae anemone, one mystery anemone,
three types of mushroom, a small colony of yellow button polyp, one
plate coral, I believe a gorgonian and another type of soft coral and
two rapidly decreasing star polyp rocks (due to hair algae). I also
have one Maroon clown, one mandarin fish, one convict goby and a few
turbo snails. I tested my water as of today, my pH was 8.4 - 8.6, 0
nitrate, 0 nitrite, 0.25 ppm ammonia possibly due to a fish death. By
the time you get this I will have done a water change and things
should be back to normal. My tank has been set up for three years, my
water tests perfect 99% of the time. Now for my questions: I have a
problem with my corals not retaining their color - almost everything
turns to eraser pink. I was told to get strong lighting hence the
VHO, still no change. I have had the lighting system one year. Is
there something I'm not adding or doing or am I destined to have a
pink tank? Next, hair, red slime and green algae, how do I get a
handle on it? It's been the death of the star polyps and nearly a
bubble coral. I have found one thing to work but am unsure if it is
safe for continued use. The phosphate filter along with red and hair
algae additive work wonders. The first time I used it with no visible
effects on my coral. I'm curious, if once the algae is gone can I
still use the sponge filter regularly to keep phosphates low? I tried
sea urchins but they don't seem to live long & turbo snails but
somebody ends up dining on them. I'm on a limited budget but anything
you can suggest would be appreciated.

Kelly Hickman
via the Internet

Wow, lots to discuss in this letter. To put it in a nutshell this
system is overloaded with respect to nutrients. You have a trickle
filter that adds nitrates to the system. You have an undergravel
filter with two inches of crushed coral that I am sure you have not
gravel washed for some time. This also adds nitrates and probably
harbours a significant amount of detritus and phosphate. You don't
use a protein skimmer, and you don't mention if you use activated
carbon. You add liquid invertebrate foods and other additives such as
Biozyme that you don't really need. You don't mention it but I assume
you are using tapwater for top-offs and for making your seawater? So
the way I see it, you are adding lots of nutrients but aside from a
monthly water change you are not exporting any. That is why you have
seen an improvement with the phosphate sponge; you have excess
nutrients, such as phosphate in your system. It does not harm the
system to use the phosphate sponge continuously. However, you should
stop and think a moment. What is causing these algae to proliferate
in the first place? If you take aspirin for a headach but it
continues to return, wouldn't you want to address the cause of the
headaches instead of just dealing with the symptom? The same applies
to your tank. You need to deal with the reasons for the algae growth.

The first thing I would recommend you do is get an efficient protein
skimmer that can turn over the entire volume of your aquarium at
least twice an hour. I would then remove the biomedia from your
trickle filter. The undergravel filter is a bit more problematical.
You should gravel wash the system at least once a week to begin with
to keep detritus from accumulating in it. Later you could probably
get away with doing it once a month or so when you do your water
change. Better yet I would remove the whole thing if you can. Stop
using the liquid invertebrate food, the corals you have probably
don't need it and it only adds to the nutrient load in the system. I
would also stop using the Biozyme, you shouldn't need it. I would
switch over to using calcium hydroxide solution to maintain your
calcium and alkalinity levels instead of the calcium and buffer combo
you are using now. It will also help to precipitate phosphate from
the water. You should be measuring your calcium, pH and alkalinity on
a frequent basis. You only mentioned your pH level which makes me
wonder what the calcium and alkalinity are; low I am willing to bet.
Finally I would look at your freshwater source. Does it contain
phosphate? nitrate? iron? silicate? These are all potential nutrient
sources for algal growth. You may need to switch to using reverse
osmosis or deionization units to ensure nutrient free freshwater. If
you do all these things then chances are you will see a rapid
improvement in your system. By using additional algae grazers such as
small hermit crabs and tangs, you will prevent the algae from
spreading throughout your system again.

Once you have your water quality and the undesirable algae under
control, you will most likely see an improvement in your coral
colours. I would also examine the iodide supplement you are using.
Does it adequately replenish the iodide in your system with the
dosage it recommends? One way to ascertain this would be to get an
iodide test kit and see what the levels in your tank are.