Koi Pond in New World Hotel, Manila (revisited)

 

I have the opportunity to stay in the New World Hotel in Manila again in November 2011 and so I went to see the Koi pond here again. Compare to the pond I saw in May 2011, the condition of the pond now is not something a pond keeper or hotel would be proud of. The water is pea-soup green and not clear like it was before.  I could not see  the bottom of the pond anymore. The Koi seems to be in distress. A koi pond is supposed to provides good feng-shui and brings good luck to the owner, but not if it is in a poor condition.

If this is your pond, what would you do?

In my earlier post, I have wrote about how to solve water quality problem in Koi pond.

Green water is caused by build up of algae, which is caused  by too much nitrate and/or waste matter in the water. Ammonia nitrate and waste matters are nutrients for algae to feed on and multiply.

First thing to do, do a water test and/or check your pond filter.  Clogged filter media would reduce the effectiveness of the biological filtration. If you are using a in-ground gravity-fed filter system, a symptom of a clogged filter would be a large difference in water levels between the pond and individual chambers of the filter. The difference is an indicator of the water resistant to water flow. Clogged filter media will not allow water to flow properly and easily through it and hence would have a higher water flow resistant. You should know the baseline or normal levels when the filter is new or well maintained. So any change in the water levels is an indicator that something is amiss. Regular filter maintenance would prevent this from happening.

Next, ask yourself when is the last time you did a partial water change? Regular partial water change is necessary, even if your filter system is functioning properly. Nitrate is a by-product of the filter system and needs to be removed by partial water change. A good filter design will make this task easy and fast.

Next, are you overstocking the pond? In the New World Hotel case, I don’t thing that is the case as the pond is quite big.

What about overfeeding? Left over uneaten food will eventually get into the filter system and impose extra workload for the bacteria in the biological filter.

If the pond water has never ever been clear and in good condition from day one, then perhaps the underlying root cause is poor filter design or pond design. In that case, major rework is needed.  Adding an external biological filter and also maybe a UV light filter as well would be quick fix.  The UV light filter will kill off the algae but this is like a fire fighting, not fire prevention.

If all else fail, rebuild the pond or cover it up with soil and try gardening instead. Maybe a Koi pond is not for you.