totally agree fish keepers are water engineers, the fish are just pretty things in said perfect water. lol the only plants i dont use fish water on are my carniverous plants. glad i can use it on the bonsai as well.

I neigther use fish water for my carnivour plants collection

Welcome to the forum!

Tropfrog wrote:

If your aquarium water is soft and healthy, water from fresh water aquariums is the best fertilizer you can give your trees.

Measuring nitrate and phosphate in the water will not only make you stay on top of maintenance of the aquarium but also give you a sence of how much fertilizer your trees gets.

Is there a reasonably easy way to measure? There are no plants in my aquariums (really, aquaria) so the water is probably real good for the trees. There is a lot of sludge that settles down, and I mix that up. I would expect that is good for the trees. They do seem to be fine, and a lot better than the years when I watered them with tap water.

Ivan wrote:

Tropfrog wrote:

If your aquarium water is soft and healthy, water from fresh water aquariums is the best fertilizer you can give your trees.

Measuring nitrate and phosphate in the water will not only make you stay on top of maintenance of the aquarium but also give you a sence of how much fertilizer your trees gets.

Is there a reasonably easy way to measure?

Depends what you mean with easy. I use common aquarium drip tests. A full analyse takes me 15 minutes. For phosphate and nitrate only it will also take 15 minutes to get the result but will involve at least 10 minutes waiting time.

I have come to understand that the kits I use is not awailable in USA. So go check what you can find in your local aquarium shop.

i only use distilled water on my carnies.

yorkyjeff wrote:

i only use distilled water on my carnies.

I feel we left the topic severals posts ago.

I use R/O water.

One more note here.

Yesterday I had a visit from a plumber who had 31 tanks of tropical fish, the largest being 240 gallons/908 liters, and a large outdoor pond with koi, goldfish, etc.

He waters all the indoors plants and outdoors flowers with fish water and waters his lawn with koi pond water, and never fertilizes with anything else. He said the analysis shows that fish water is a balance of all the primary nutrients.

I would expect there are trace elements missing, but I don't know what. I didn't ask him.

Trace elements are most likelly present. However, many of them may be non mineralized and therefore not awailable to plants. For lawn and flower beds that is not an issue. Mineralization happens in healthy organic soil. For bonsai in mostly inorganic soil mix, it may not be awailable to the trees.

Tropfrog wrote:

Trace elements are most likelly present. However, many of them may be non mineralized and therefore not awailable to plants. For lawn and flower beds that is not an issue. Mineralization happens in healthy organic soil. For bonsai in mostly inorganic soil mix, it may not be awailable to the trees.

Can you get fertilizer that is just trace elements? I guess somewhat like Biogold and fish ware would not overload nitrates, potassium, and phosphates?

Ivan wrote:

Tropfrog wrote:

Trace elements are most likelly present. However, many of them may be non mineralized and therefore not awailable to plants. For lawn and flower beds that is not an issue. Mineralization happens in healthy organic soil. For bonsai in mostly inorganic soil mix, it may not be awailable to the trees.

Can you get fertilizer that is just trace elements? I guess somewhat like Biogold and fish ware would not overload nitrates, potassium, and phosphates?

Most fish tank fertilizers are just trace elements since most fish tanks do not need extra macro nutritions.

There are also trace element fertilizers for agricultural needs. They often come in far too big packages than we will use in a life time. Within the aquarium hobby there are people and companies that split it into smaller packages and sell. Tom Barr is an american that advocate the use of theese products. You may find someone selling small packages throu his forum called barr report. The two most common is nutrisi and micro+.

Do not ask me how to properly dilute it for bonsai. All I can say is that if you dose according to the instructions of estimated index in your aquarium and use waste water for your bonsai you will not overdose. And your aquarium plants will thank you.