Trouble keeping pond plants alive

[Reflections]

Hi everyone, please be gentle with me, I'm a newbie. We recently setup quite a big pond, 15000ltrs, it has uv light and pond one filter, a circulating pump, and small water fall, we already had some lillies and lotus in a smaller concrete trough and since moving them into large pond have flowered happily, but anything else we put in seems to just die slowly. I have put fert tabs in them, I've altered water levels so they are not as deep, what else could I try to improve on. Thanks

 

[Marck]

Greetings, welcome to the Forums.

Tell us more.
What kind of plants were they? Is your pond full in full sun? Have you tested the water? Do you keep fish?

 

[Reflections]

Hiya, sorry yes I should have submitted abit more info
Ph is 8.8 this evening
Kh is 1
I don't have any other tests. Pond is 4mths old, we are in new zealand so we started it in full summer, and yes full sun, also is abit exposed to wind. We put no fish in purposely as we wanted to wait till it cycled but about 5 small goldfish somehow came over with some lillies we shifted, must have been caught up in leaves etc, they haven't been seen since as the pond immediately turned green, even though we have uv and a huge filter, but from reading articles, this is to be expected with new ponds in summer.
We brought lots of plants, some marginal and others deep water, but all seem to just go yellow and slowly get worse, never thrive, everyone tells me to add more plants to get pond to balance itself, but I'm seeing they aren't doing very well so no point in keep adding them to see them die, not to mention they also expensive!. Pond pickerel, grasses, water iris, black taro, others but I don't know the names. I'm wondering if I'm am placing the marginal to deep, I try to keep them half out of water, bog plants are outside the pond in their own wet area, otherwise it's just Lillies and lotus in deep-water.

 

[SarahT]

Welcome to the forum. Interesting question. I'm not a pond plant expert, but here's my thought. Without much of a fish load and a new pond, I wonder if there are sufficient nutrients for the plants. Did you plant with pond plant fertilizer? If the "not much nutruent" is right, more plants would more likely worsen the problem. (Sorry if I'm not much help.)

 

[addy1]

Welcome to the forum!

Sounds like not enough food for the plants. Mine were yellowish before my fish load got bigger.

 

[Mmathis]

Do you have any fish in your pond?

 

[j.w]

@Reflections
I might think that you should use a different kind of fertilizer. One that works instantly. Maybe even start the plants in a different container of water and use some liquid fertilizer to give them a big boost before putting them in a pond. Not sure on this but try it on maybe one plant or so.

 

[Reflections]

Do you have any fish in your pond?

Only 5 small ones who were accidentally introduced.

 

[Reflections]

Welcome to the forum!

Sounds like not enough food for the plants. Mine were yellowish before my fish load got bigger.

OK, cool, I'll try to get some fert tabs into them today. Thankyou

 

[Reflections]

Welcome to the forum. Interesting question. I'm not a pond plant expert, but here's my thought. Without much of a fish load and a new pond, I wonder if there are sufficient nutrients for the plants. Did you plant with pond plant fertilizer? If the "not much nutruent" is right, more plants would more likely worsen the problem. (Sorry if I'm not much help.)

the other 3 replies all say the same as you, with no fish load, plants might be hungry. So I'll try that as my first action. Thankyou

 

[adavisus]

A ph of 8.8 is too high for most aquatic plants which evolved usually in the 5.5-7.5 range. They are unable to metabolize nutrients and starve.
If you dunk a sack size bag of peat with a few holes poked in it, that would gently release and adjust your ph levels

 

[Reflections]

OK, that's probably my problem then. I'm in New zealand and never seen a bag of peat for sale. What else will bring ph down naturally. Thankyou

 

[Reflections]

Is this what you mean

 

[Reflections]

Or someone said white vinegar to lower ph too?

 

[adavisus]

Anything acidic will work, you might want to dilute nitric, sulphuric, hydrochloric acids before putting them in. Those and vinegar are usually cheap to find at chemical labs.

Any kind of peat is a gentle way to do it, plus you get to use it up potting plants

You may want to check what is the source of the high ph, very hard water supply, cement work perhaps?