Hi from New Zealand

[callingcolleen1]

Yes these things do kill the aphids nice, but the ants will carry more up the tree to "farm them". So if you put sticky tape on the truck of the tree the ant's will not get past the sticky tape and bring more aphids. If it is a bush they you will have to move the ants cause they bring most of the aphids back and re-infect the plant. Good luck with the aphids, I gave up and now let the ants have one sacrificial plant, a goose berry bush, that I still get a good harvest from, cause the ants know if they kill the bush their "pet aphids" won't have a place to get food from!

 

[Waterbug]

Glad you dropped in on this one WB.

Thanks for the kind words. I have to give a lot of credit for what I know to RichToyBox at Koiphen. I've learned a lot from a lot of sources about concrete but Richard ties it together with ponds and takes the time to explain it all in extreme detail. So if anyone wants to go straight to horse's mouth Richard is your guy.

 

[Waterbug]

In retrospect, I rushed things.

For those keeping score that's 127,827,938 people who rushed it and 0 who didn't.

Like you suggested, I am running tests on my tap water. The first 24hrs is done (without the concrete blocks) with pH changes matching my pond.
pH test day 1

Thanks for doing the test and posting results. But I wasn't 100% sure what you meant. Did the pH in the bucket increase? From what to what. I saw the photo but don't know what goes to what. Maybe something like:

Bucket only test
Tap pH: ??
24 hrs pH: ??

I will introduce the blocks that I had my Lotus and submersible pumps sitting on when I return from work in a few days. I'm very interested to see if there is any change over time.

This type of test does vary depending on the block, aged vs new, type of mix used, how dense, etc. Blocks are normally very porous so you're performing the absolute best case for raising pH. What I'm hoping you see is the speed at which pH raises and to what degree. Pretty much anything you do will affect pH, even simple stirring. So it's difficult to predict the results. But what you should see for sure is that pH doesn't go to concrete's pH of 13. Where exactly it ends up depends on other substances in the water. You could see pH go up a lot, maybe 10 even 11 with a new block. It depends on the amount of CO2 in the water which turns the calcium hydroxide (12.4 pH) leaching out of the concrete to calcium carbonate 9.4 pH. If you have a small pump that you can place in the bucket that would help keep CO2 levels up.

But here's what you probably won't see. 12.4 pH. The block dissolve.

Knowing the GH of the water also can tell you something. Higher GH can keep pH from going above 8.4 depending on what else is in the water.

I look forward to your readings no matter the result. Plain water in the bucket is an easier, more reliable test. The concrete block is more of a variable, but all data is good data.

Reading up on pH buffering is kind of important imo, much more important than the concrete issue. It can be a little tricky, but once you decide on how you want to keep your pond it can be very simple. For example, although concrete can raise pH, that's actually a good thing because it acts as a pH buffer to some degree. It isn't a very good pH buffer but better than nothing. So although 9+ pH can be alarming at first, once your pond is producing acid the concrete will help a little. But better to have proper pH buffering.

 

[Waterbug]

Out of curiosity I tested the very green water from his pond both last night and this morning. It went straight off the high pH scale last night and this morning it had dropped significantly and ended up the same pH as mine @ 7.8. Considering it's mid summer here with a lot of growth activity. Is it safe to assume these large daily pH swings are normal?

Yes, that would be normal in a green pond. There is also a pH swing in clear ponds but normally not as extreme. Here's an explanation. Basically the algae consume CO2 and produces O2 during the day. Less CO2 = higher pH so by the end of the day pH is maxed. At night algae consumes O2 and produces CO2 which drives down pH. And of course fish are producing CO2 24/7 and decomposition of organic matter also adds CO2 24/7. Think of CO2 as an acid, which it is in water.

Hooking this back to concrete, the CO2 produced reacts with the calcium hydroxide (lime) coming out of the concrete turning it into calcium carbonate (limestone, oyster shell, etc.). The calcium carbonate builds on the pores of the concrete plugging them so less and less calcium hydroxide can escape. This is why concrete is self sealing. Without that concrete would in fact continue to leach calcium hydroxide and breakdown. Concrete would be pretty worthless without this process because it happens in the air too. Air is about 5.6 pH, well moisture in air anyways.

BTW, some pond keepers add oyster shell to their ponds as a pH buffer. Made of calcium carbonate...the same stuff the surface of concrete becomes in water. Kind of weird that oyster shells are considered a benefit while the same person will consider concrete toxic. I think oyster's just have a better PR department. Also why oyster shell and concrete are poor pH buffers, because calcium carbonate is slow to react with acid.

Next Myth
If you want to get a jump on the next myth take a measure of ammonia and nitrate in your friend's green pond and your clear (I assume) pond, or tap water even. The green pond will have 0 ammonia and 0 nitrate I'll wager. Yours will have solid nitrate (if your tap water has nitrate, not sure about New Zealand). As or if your pond goes green your nitrate will drop to zero. But you will read many places that plants will suck the nutrients (nitrate) out of the water and kill the algae. You'll have shown yourself that isn't true and can save you a lot of hassle screwing around with that myth to clear a pond. just trying to get the jump on the next thing.

 

[MarcusNZ]

Thanks for doing the test and posting results. But I wasn't 100% sure what you meant. Did the pH in the bucket increase? From what to what. I saw the photo but don't know what goes to what. Maybe something like:

Bucket only test
Tap pH: ??
24 hrs pH: ??

The tap water pH in the the bucket was 7.6 after 24hours (no block) which matches my morning pond pH.
After adding the cinder block, the pH climbed each morning to the point where by day 8, my test kit was at its limit (8.8pH).

I applied the pond sealer to the concrete parts of the waterfall but have yet to build up the courage to start using it again. I still have the pond recirculating through a filter with a fall from the hose into the pond. The fish love playing in this little jet stream...


Fish. Things have been great for the fish over the last month or so. We have had close to record low amounts of rainfall since November. The fish seem to be coping well with the long fine days. I introduced 12 new fry from a friend a few weeks ago and they have adjusted well. I initially kept them separate for two weeks because they were quite small (no colour). I'm confident they have all survived and not fallen victim to the bigger fish or the pump. The runt of them all does not appear to have grown much which seems odd (maybe I'm losing my eyesight). The others are all changing colour and growing quite nicely.

Next Myth
If you want to get a jump on the next myth take a measure of ammonia and nitrate in your friend's green pond and your clear (I assume) pond, or tap water even. The green pond will have 0 ammonia and 0 nitrate I'll wager. Yours will have solid nitrate (if your tap water has nitrate, not sure about New Zealand). As or if your pond goes green your nitrate will drop to zero. But you will read many places that plants will suck the nutrients (nitrate) out of the water and kill the algae. You'll have shown yourself that isn't true and can save you a lot of hassle screwing around with that myth to clear a pond. just trying to get the jump on the next thing.

I did test his and it had a trace amount of Ammonia. Everything else was a scratch.
My pond has a scratch on Ammonia, Nitrites and Nitrates and the water is crystal clear to the bottom (900mm deep). There is a good coating of agae on the liner with more and more string algae also growing so I have started taking the odd bit of string algae out.

 

[callingcolleen1]

Little bits of string algae OK, but if you get too much long stringy stuff, you can reach down into pond with a long stick and twirl it around like green "cotton candy" and rid the pond of the excess algae that way. Also fish will eat string algae so don't over feed the fish and make them eat the algae too.
If you plant big sedges and get them going the sedges will help to starve out the algae once they are fully established, may take a couple seasons to get a good size clump so get started on some sedges today!
Sedges are pond plants with a "spear shaped leaf, such as cat-tails, water Iris, grasses, and rushes. You may find local sedges nearby or get them from a garden centre.
Sedges can be planted in mesh plastic baskets that allow the roots to grow out. Plain kitty litter may be used as planting soil. You can also line the basket with brown paper and that will stop fine particals from getting out. Plant's love to grow thru paper pulp and it will not hurt your pond. Place the basket in the water on a shelf, if you have koi, place the top of the basket near water level so the koi cannot get into the basket and make a mess.

 

[Waterbug]

After adding the cinder block, the pH climbed each morning to the point where by day 8, my test kit was at its limit (8.8pH).

Thanks for the info. I would have expected a bit higher pH with the cinder block, but they're so variable it's hard to predict. It does show what's been known about cement for decades, outside of pond forums, it doesn't drive pH to dangerous levels.

 

[Dave 54]

city water usually has chemicals in it and needs pretreated .Gold fish are not as fussy about water quality as koi are ,I have both .I use quilt batting to prefilter fine stuff out .I waited 2 months but I also used some of the water from the old pond to seed the filter and to help it start it's bio load .Adding water with out testing can cause fish loss if not tested and pretreated .

Wont find any koi for sale in New Zealand sissy they are banned and hunted down and destroyed as pest that are wreaking havock on the native species of New Zealand since they escaped into the wild , they organise bow and arrow shoots to try and destroy them .
Sadly its an uphill struggle that I doubt they will win
rgrds
Dave

 

[Dave 54]

Thanks for the info. I would have expected a bit higher pH with the cinder block, but they're so variable it's hard to predict. It does show what's been known about cement for decades, outside of pond forums, it doesn't drive pH to dangerous levels.

No Warerbug but newly made concrete ponds that are not treated can cause serious burns to fish so they must be treated before adding fish otherwise your asking for trouble
rgrds
Dave

 

[gardengimp]

What causes the burning?

 

[Dave 54]

We had a case of mysterious burns on koi from a womans koi in South africa burned clear through the koi's mouths.
If I remember rightly its something in the make up of the cement you can leave the pond open to the elements for a few months with no water or there's a solution you paint over the cement to negate it .
Will have to go back through some threads on two sites to dig out the answer might take a while but I'll get back to you if thats ok
rgrds
Dave

 

[Dave 54]

Found it for you on my good friend Pieter Odendaals South african site saldy the lady got very disruptive on the site then my own and another US site and was banned from all three for being highly disruptive on all three and got it into her head she knew better than koi keepers who like myself had years of keeping behind us (she had 11 months keeping thats all )....
Hope it helps you clarify things

rgrds
Dave

I had a new take on my mouth rot. This is what Dr. Novac told me about it:
What you’re Koi have is something that most hobbyists haven’t experienced in probably over thirty-year or more in the US, mouth lime burn disease. It’s caused by your cement pond not being cured properly before you placed your animals into your pond. In Victorian times, this was not that uncommon for their fish to get lime burn disease (it really is not a disease at all) until their pond cured and sealed. You have an improperly cured pond, and it’s literally burning the soft tissues of the inner and outer parts of the mouths of your Koi from calcining lime consisting of calcium oxide. Lime is used in the states to make soil sweet or reduce acidity in soil. Henceforth, it will make pond water pH go off the charts with high alkalinity of 8.9 or higher. One trick is to use vinegar to help stabilize pH, but this is not a long-term fix.

Every bag of cement in the US has warnings about getting cement into your eyes or on hands for any prolong periods of time and to use protective gloves.

Curing a pond takes a long time of filling the pond, them scrubbing it down and then emptying it out and going through process several times until the pH stabilizes to the same as that of the tap water use to fill the pond. This could take up to a year of curing the pond before it is safe for fish. For you, you would have to drop the pH to a lower level than your tap water to see if it elevates once again to unacceptable levels within 24 hours. If it does, your pond is not cured.

Algae on the sides of the walls of the pond are not an indication that all is well and there are several strands of algae that can tolerate acidic waters as well as alkaline waters, too. The algae on the sides are not going to protect your Koi from the burns they are receding, I’ve seen this before on fish and it was always an improperly cured cement pond. Once the pond was sealed with clay or a commercial sealer the problem subsided.

 

[MarcusNZ]

Thanks for the info. I would have expected a bit higher pH with the cinder block, but they're so variable it's hard to predict. It does show what's been known about cement for decades, outside of pond forums, it doesn't drive pH to dangerous levels.

There is no way of knowing what the pH peaked out at as my kit only reads up to 8.8pH.

Wont find any koi for sale in New Zealand sissy they are banned and hunted down and destroyed as pest that are wreaking havock on the native species of New Zealand since they escaped into the wild , they organise bow and arrow shoots to try and destroy them .
Sadly its an uphill struggle that I doubt they will win
rgrds
Dave

You are quite right there Dave. Here is a snippet from our (NZs) Department of Conservations website.

Approval from the Minister of Conservation or Minister of Fisheries is required if you want to
introduce aquatic life into any waterbody. Failure to obtain the required approval can result in a
fine under the Conservation Act 1987 of up to $5000.
Koi carp, gambusia and the aquatic weeds listed in this brochure are classified as Unwanted
Organisms under the Biosecurity Act 1993. People caught displaying, releasing, spreading, selling,
or breeding them without an approval under the Biosecurity Act are liable, on conviction, to a
fine not exceeding $100,000 or imprisonment for a term not exceeding 5 years, or both.
Koi carp and rudd (outside of the Auckland/Waikato Fish and Game region) are classified as
noxious fish under the Freshwater Fisheries Regulations 1983. People are liable to a fine of up to
$5000 who, without permission, possess, have under control, rear, raise or consign these fish.

That said, you will not catch me even entertaining the idea of catching some out of the river to keep in my pond. I'm happy with goldies :goldfish:

 

[MarcusNZ]

Curing a pond takes a long time of filling the pond, them scrubbing it down and then emptying it out and going through process several times until the pH stabilizes to the same as that of the tap water use to fill the pond. This could take up to a year of curing the pond before it is safe for fish. For you, you would have to drop the pH to a lower level than your tap water to see if it elevates once again to unacceptable levels within 24 hours. If it does, your pond is not cured.

Algae on the sides of the walls of the pond are not an indication that all is well and there are several strands of algae that can tolerate acidic waters as well as alkaline waters, too. The algae on the sides are not going to protect your Koi from the burns they are receding, I’ve seen this before on fish and it was always an improperly cured cement pond. Once the pond was sealed with clay or a commercial sealer the problem subsided.

Wow, A whole year! :banghead3:
Like I said in an earlier post, I have sealed the waterfall with a pond sealing paint for now. I will keep it isolated and test water that sits on it over time and see how it looks before reintroducing it to my pond loop.
Thanks for the information Dave.

 

[Waterbug]

No Warerbug but newly made concrete ponds that are not treated can cause serious burns to fish so they must be treated before adding fish otherwise your asking for trouble

Just a myth Dave. Untreated concrete fish ponds have been in use for several hundred years. Long before EPDM and sealers were ever invented. Here's the sticky concrete thread on Koiphen. Rich also explains in detail the chemical reaction in other threads. And there are also many construction focused web sites that explain why concrete doesn't dissolve in water, here's one.

The basics are the lime (calcium hydroxide, the high pH "burning" stuff) combines with CO2 in the water (or air) to form basically limestone (calcium carbonate). The calcium carbonate basically seals the concrete and stops additional lime from leaching. Lime does continue to leach for decades but at very small amounts and act as a pH buffer since all ponds will naturally head to low pH on their own. However, concrete is extremely slow to produce calcium carbonate and therefore an extremely poor pH buffer. Concrete ponds generally require additional pH buffering to keep pH from crashing.

The concrete myth was widely repeated in pond forums 10 years ago but fortunately not as much any more. There are still plenty of wild and strange ideas out there on concrete.

Every bag of cement in the US has warnings about getting cement into your eyes or on hands for any prolong periods of time and to use protective gloves.

A bag of cement, mortar or concrete contain ingredients one of which is lime, bad stuff. When water is added a chemical reaction happens and the properties change. Which is why the ingredients are nasty but you can sit on concrete patio around a swimming pool and not be "burned" and why the warning labels on bags of cement mix are not also on sidewalks, concrete park benches, etc.

Curing a pond takes a long time of filling the pond, them scrubbing it down and then emptying it out and going through process several times until the pH stabilizes to the same as that of the tap water use to fill the pond.

Actually scrubbing is the worst thing you can do, that will increase leaching because it removes the protective calcium carbonate layer, the "sealer".

This could take up to a year of curing the pond before it is safe for fish.

Any source for this? I know the web has a lot of far out "facts" but that one is really out there.

Algae on the sides of the walls of the pond are not an indication that all is well and there are several strands of algae that can tolerate acidic waters as well as alkaline waters, too.

What species [strands]? I've read a lot about algae (such as here) not being able to handle pH in the range that would cause burns on flesh (over 10 to even start to be a concern).
There are blue-green algae that live in high pH environments but "blue-green algae" are cyanobacteria. Despite their common name these are bacteria, not plants, and sure not the green stuff growing on the sides of ponds. That stuff is a plant.

At some point even commonsense has to start kicking in. Algae (eukaryotes) are pretty simple plants with very little protection. They don't have bark or layers of different kinds of cells as protection. The concept that these plants can survive growing on a surface with a pH so high that fish get burned when only in occasional contact is beyond logical.