I have successfully combatted the algae, but they have come back. Why have they returned and how can I prevent it?
The main cause of algae in garden ponds is too much light and too many nutrients. When combatting the algae, the nutrients bound in them are released, but then during the next spell of fine weather with sufficient light these nutrients are in the pond again ready to feed the next algae attack.
Preventive measure: JBL PhosExPond direct precipitates phosphates, they are removed from the water and from the algae. JBL PhosExPond filter permanently binds phosphates and limits their value. Having dealt with the algae JBL BactoPond can then be applied to minimize the nitrigen compounds. JBL SediExPond helps reduce the sludge at the bottom of the pond with its heterotrophic (all eating) strains of bacteria.
JBL AlgoPond Sorb adds natural humic substances to the water and through its slight amber colouring reduces the excessive amount of light entering the garden pond. This in turn results in a significant reduction of algae growth.
I used AlgoPond Direct and the thread algae died. But they have come back and phosphate is not detectable.
This last statement is probably right according to the user’s measurement, but factually incorrect. Phosphates are always present. They are not only in the free flowing water but also in the pond sludge, as mineral-based components in the pond water (though not indicated through PO4 tests) and there is a permanent replenishment of phosphates. Furthermore many algae species can store phosphate in great quantities, some of them up to 100,000 times of their own requirements. This depot is for “hard times”. It only needs surviving algae spores, which can grow again. There is no certainty that a single application of AlgoPond Direct keeps the pond free of algae for the whole season. This would be good but can’t be guaranteed for biological reasons.
Can I use JBL PhosEx Pond Direct directly after JBL AlgoPond?
Do not use JBL PhosExPond Direct directly after JBL AlgoPond Forte. It is better to wait for about 3-4 days, until the algae have been visibly reduced and the nutrients, stored in the algae cells, have been released. Only then is the phosphate precipitation with JBL PhosExPond Direct useful and effective.
The same also applies to the control of thread algae with JBL AlgoPond Direct and the follow-up treatment with JBL PhosEx Pond Direct.
How much time should pass after the application of JBL PhosEx Pond Direct before the UVC water clarifier can be put back into operation?
There is no general answer to this question.
JBL PhosEx Pond Direct binds the soluted phosphates present by means of a chemical precipitation, which means a transformation into a non- (or under certain chemical conditions) water soluble form. How much time now has to pass before a UVC water clarifier is put again into operation strongly depends of the circulation rate, which means how long it needs till the whole water has passed the pond filter.
Furthermore the existing current / water movement in the pond and the way that JBL PhosEx Pond Direct is added has to be taken into consideration. The time period is shorter with an extensive distribution, i.e. with a (plastic) watering can and with a good water movement than with an addition concentrated in one spot in a garden pond with slow water movement.
Besides the distribution the water temperature is also relevant (though this only needs to be mentioned in passing here).
The switch-off period needs to be at least twice as long as it takes for the pond water volume to completely circulate. To be on the safe side with the phosphate precipitation a turn-off time period of 48 hours can be considered as being sufficient.
Can the pond care products JBL StabiloPond Basis, JBL StabiloPond KH, JBL OxyPond, JBL FilterStart Pond, JBL AlgoPond Direct*, JBL PhosEx Pond Filter, JBL SediEx Pond, JBL AlgoPond Sorb, JBL AgoPond Forte*, JBL AlgoPond Green*, JBL PhosEx Pond Direct and JBL BactoPond be used with an operating UV-C water clarifier without any problems or should the UV-C unit be switched off?
In simple terms we can say that with the application of the liquid products JBL AlgoPond Sorb, JBL AgoPond Forte*, JBL, AlgoPond Green*, JBL PhosEx Pond Direct, JBL BactoPond the UV-C water clarifier should be temporarily switched off so that the active substances will not be destroyed. Please look up the time periods in the respective operation instructions.
With JBL StabiloPond basis, JBL StabiloPond KH, JBL OxyPond, JBL FilterStart Pond, JBL AlgoPond Direct*, JBL PhosEx Pond filter, JBL SediEx Pond the UV-C water clarifier may remain in operation.
* Labelling according to EU Directive 98/8/EC: Use biocides safely. Always read the label and product information before use!
Even after multiple applications of PhosEx Pond Direct, the phosphate test still indicates a deep blue as maximum value.
This means the phosphate value was so high, that the application of PhosEx Pond direct was not detectable in measurements. The value of the dissolved phosphate was simply several times higher. In this case it’s best to dilute the water sample with distilled water or another phosphate-free water before the test, in order to determine the real phosphate value.
Alternatively PhosEx Pond Filter can be very useful.