22
aquaria algae can completely cover the glass, stones and even plants,
leading to their death. In a marine tank algae can overgrow corals to
such an extent that the corals suffocate and die.
Although nitrate is basically not toxic, it is highly desirable to keep the
level low to prevent algae growth. For fresh water we advise a threshold
of 50 mg/l and for sea water 10 mg/l. This can best be accomplished
by refreshing water; fi rst check the nitrate level of the refreshing water.
Phosphate (PO
4
)
Test procedure:
1. Take a water sample of 10 ml.
2. Add 5 drops of PO
4
-1 test fl uid and shake.
3. Add 5 drops of PO
4
-2 test fl uid and shake again.
4. Add 2 spoons of phosphate powder (tube with blue cap) and shake.
5. Wait 10 minutes.
6. Determine the PO
4
-value using the included colour chart.
Phosphate (chemically abbreviated as PO
4
) is one of the waste products
produced by fi sh. Phosphate is not toxic for fi sh and and thus is no di-
rect problem for the health of fi sh like ammonia or nitrite are. Indirectly,
phosphate can lead to algae problems as phosphate like nitrate is one
of the key nutrients for algae and plants. Plants and algae compete
with one another for nutrients and unfortunately plants can’t always win
20ml
15ml
10ml
5ml
10 min
6
5
3
5 dr
ops
20ml
15ml
10ml
5ml
2
10 ml.
20ml
15ml
10ml
5ml
1
4
PO
4
-1
5 dr
ops
20ml
15ml
10ml
5ml
PO
4
-2
20ml
15ml
10ml
5ml
2x
