Koi Ponds

[bkkmadness]

Dr. Naam,

Looks like the algaecide wasn't a good idea, I did say they could give mixed results but losing fish is an extreme one. I've never had experience with these Thai made algaecides before but I used to sell European manafactured brands and some were very strong herbicides, and a strong chemical to add to the water for sure. Remember whatever chemical you add to your pond will effect the fish greatly because it's there total enviroment. You're aware to how sensitive you would be if the air around you was changed, it's the same thing.

Glad to hear you are emptying the pond, best course of action. Not pleased to hear you want to get rid of your fish though. I know you lost a few and it ain't nice and you may lose a few more due to this and the added stress that comes with catching them and transfering them etc. but you've only had a minor mishap, and be a shame to ruin your dream for a beautiful koi pond because of it.

So empty the pond, (wherever you keep the koi whilst you are doing this keep them in a dark covered place) and then fill it up again. Get the pump running with the UV light and filter (24/7 365 days a year, non stop). Get those koi back in the pond, and don't worry about the chlorine because it disperses after a few hours anyway.

Now as I said you might lose a few more koi over this time, but not much you can do about that. From now on for the next couple of weeks feed the koi once a day. I don't know how much you know about this so apologise if it seems I'm talking down to you, but the filter is a biological system, it relies on bacteria to help break down poisons (from fish waste) in your pond. You need to cultivate that bacteria by running oxygenated water past it and feeding it (on fish waste). But you can't overload the system because there is too much fish waste for the bacteria to handle and it'll build up and kill the fish.

At the moment you have no bacteria in there, you have to build it up slowly so be careful not to overfeed or over stock (ie. add new stock) to your pond just now.

Just leave your pond after that, don't chuck any quick fix chemicals in the pond, just leave the filter running, feed the fish once a day and don't add any more fish. It'll settle down and the fish will be fine, and maybe you'll get algae and maybe you don't but you can tackle that later. Maybe the UV takes care of it, maybe it doesn't, you do have a massive pond well exposed to light, it's gonna be the biggest problem you have.

I would still say now though, especially since you have tried the algaecide route, that you should try to find a source for a large amount of aquatic plants to solve that green water problem. If you can get the balance between the fish/filter/plants right you have a great pond, crystal clear with healthy fish.

I think you're in Patters, and I think you have a gardener, ask him about getting a few bin bags worth of local lake plant to chuck in your pond. It'll cost a few thousand baht but the koi will not be able to eat it fast enough coz some of those plants are real fast growers.

Good luck and don't lose heart.

[Naam]

Dr. Naam,

Looks like the algaecide wasn't a good idea, I did say they could give mixed results but losing fish is an extreme one. I've never had experience with these Thai made algaecides before but I used to sell European manafactured brands and some were very strong herbicides, and a strong chemical to add to the water for sure. Remember whatever chemical you add to your pond will effect the fish greatly because it's there total enviroment. You're aware to how sensitive you would be if the air around you was changed, it's the same thing.

Glad to hear you are emptying the pond, best course of action. Not pleased to hear you want to get rid of your fish though. I know you lost a few and it ain't nice and you may lose a few more due to this and the added stress that comes with catching them and transfering them etc. but you've only had a minor mishap, and be a shame to ruin your dream for a beautiful koi pond because of it.

So empty the pond, (wherever you keep the koi whilst you are doing this keep them in a dark covered place) and then fill it up again. Get the pump running with the UV light and filter (24/7 365 days a year, non stop). Get those koi back in the pond, and don't worry about the chlorine because it disperses after a few hours anyway.

Now as I said you might lose a few more koi over this time, but not much you can do about that. From now on for the next couple of weeks feed the koi once a day. I don't know how much you know about this so apologise if it seems I'm talking down to you, but the filter is a biological system, it relies on bacteria to help break down poisons (from fish waste) in your pond. You need to cultivate that bacteria by running oxygenated water past it and feeding it (on fish waste). But you can't overload the system because there is too much fish waste for the bacteria to handle and it'll build up and kill the fish.

At the moment you have no bacteria in there, you have to build it up slowly so be careful not to overfeed or over stock (ie. add new stock) to your pond just now.

Just leave your pond after that, don't chuck any quick fix chemicals in the pond, just leave the filter running, feed the fish once a day and don't add any more fish. It'll settle down and the fish will be fine, and maybe you'll get algae and maybe you don't but you can tackle that later. Maybe the UV takes care of it, maybe it doesn't, you do have a massive pond well exposed to light, it's gonna be the biggest problem you have.

I would still say now though, especially since you have tried the algaecide route, that you should try to find a source for a large amount of aquatic plants to solve that green water problem. If you can get the balance between the fish/filter/plants right you have a great pond, crystal clear with healthy fish.

I think you're in Patters, and I think you have a gardener, ask him about getting a few bin bags worth of local lake plant to chuck in your pond. It'll cost a few thousand baht but the koi will not be able to eat it fast enough coz some of those plants are real fast growers.

Good luck and don't lose heart.

thanks for your concern. the algaecide worked but (again) stupid me had no bloody idea how to apply as all instructions were in thai. now i learned that the grains should have been dissolved and applied to the water through a cloth strainer to avoid that the fish mistake them for food.

we have started cleaning the pond yesterday but it's a quite tedious work as the bottom is full of muck. will finish most probable today or perhaps tomorrow. by the way, the surviving fish (about 40 of them) seem to be quite happy.

another problem occured that all my floating plants (they look like flowers and started to spread very fast) died over night when i filled up the pond partly with my well. the well water has an extremely low pH (5.8) and the sudden change in pH must have been the reason.

will report further on any progress.

[Naam]

Filter sizes and pump flow rates for different sized ponds are given assuming the pond will be stocked to it's maximum level.

You can certainly reduce filter sizes as long as you stock sensibly.

In fact with that size pond you could get away with quite a lot of fish without the need for a filter system at all and they would be perfectly healthy, though in this case plants would be advised to help keep the 'balance' of the pond.

The balance is the key thing any fish keeper is looking for whether they have a 10 gallon fish tank or a 20 000 gallon pond, keeping those the ammonia/nitrite and nitrate levels down are essential to a well balanced healthy environment for the fish and it'll cut down the amount of algae as well.

i have approximately 30 kois in it, size between 15 and 25 cm. definitely not overstocked. am i right or wrong?

correction! with the water now much clearer i counted more than 40 kois, some of them >35cm in length.

[Jai Dee]

I'm in a similar position.

I've drained my pond completely and scrubbed all the concrete and stone surfaces free of all algae. I let it dry for a couple of days and then filled up the bottom 2" with water and added a handfull of copper sulphate to it. I brushed the mix all around the bottom and walls to make sure that all remaining algae would die. I then refilled the entire pond and have added a couple of plants in pots (so the earth doesn't dirty up the water). I have not reintroduced fish yet.

I now want to add some surface aquatic plants to keep the sunlight down. I figure that if I start near the bottom of the Darwin chain and get a healthy plant/water micro-environment going, I should then be able to inroduces higher species later... small fish followed by larger fish etc.

Has anyone got any ideas of where I could get some of these surface type aquatic plants in the Pattaya/Sattahip area?

[Naam]

I then refilled the entire pond and have added a couple of plants in pots (so the earth doesn't dirty up the water). I have not reintroduced fish yet.

but how will you prevent the earth in the pots from diluting and mucking up the water?

[Jai Dee]

I then refilled the entire pond and have added a couple of plants in pots (so the earth doesn't dirty up the water). I have not reintroduced fish yet.

but how will you prevent the earth in the pots from diluting and mucking up the water?

Add 1"-2" of small stones/rocks to the top of the soil level. Not too heavy to prevent new growth from pushing through.

[Naam]

I then refilled the entire pond and have added a couple of plants in pots (so the earth doesn't dirty up the water). I have not reintroduced fish yet.

but how will you prevent the earth in the pots from diluting and mucking up the water?

Add 1"-2" of small stones/rocks to the top of the soil level. Not too heavy to prevent new growth from pushing through.

that's what i did but the water flow of the filtration washed out not only earth but clay too

[bkkmadness]

I then refilled the entire pond and have added a couple of plants in pots (so the earth doesn't dirty up the water). I have not reintroduced fish yet.

but how will you prevent the earth in the pots from diluting and mucking up the water?

Add 1"-2" of small stones/rocks to the top of the soil level. Not too heavy to prevent new growth from pushing through.

that's what i did but the water flow of the filtration washed out not only earth but clay too

Did you use sacking in the pots to prevent the soil from coming out of the side? Other than that Jai Dee is right with adding the stones on top, as long as the fish don't dig through them.

And 40 Koi at 35cm is still fine for your pond.

Refill it and let it settle down again.

[Naam]

"Did you use sacking in the pots to prevent the soil from coming out of the side?"

i did not of course how come you people have all these brilliant ideas and i don't?

latest development. pond is clean. all fish survived. have started filling up.

surprises:

-bought three fish (species unknown) when pond was established one year ago. size was appoximately 10-12 cm each. now they have become monsters, each weighing about 3 kilograms . we caught them and the gardeners wife is busy frying them.

-bought half a dozen "algae eaters" which are normally kept in aquariums (also one year ago). size 6-8cm. now there are 18 of them in pond, each ~30cm long. the LORD works in miraculous ways!

no surprise: hundreds or thousands of tiny fish (size 1cm) where pumped out

[bkkmadness]

Ok, so that's gonna be the soil problem solved in the future, tick it off the list!

The fish your gardner's wife are frying look like Pacu, a good idea to remove them from your pond. Not only will they eat more vegetation than the Koi they will grow to about 3 feet and get a bit bothersome with the Koi along the way. I'm not 100% sure they are Pacu though. Anyway, should taste nice at that size.

The sucker fish you have are Plecostomus, they'll double their size again perhaps in as little time as a year.

Where did all the baby fish come from though? Were they Koi?

[Naam]

1) The sucker fish you have are Plecostomus, they'll double their size again perhaps in as little time as a year.

2) Where did all the baby fish come from though? Were they Koi?

1) can i leave them in the pond? it would be quite easy to catch them now. my "domestic couple" would like the latter very much. both of them like fish on their plates

2) it's not a big problem for me to explain Einstein's relativity theory or the difficulties in designing the various cooling cycles of a nuclear power plant but in this respect my best guess is that some of my male and female fish got together and had some fun (sort of)

3) "sacking" the plants what kind of fabric would you suggest? doesn't it have to be tight woven that earth is not dissolved and "leaking"?

[bkkmadness]

1) can i leave them in the pond? it would be quite easy to catch them now. my "domestic couple" would like the latter very much. both of them like fish on their plates rolleyes.gif

2) it's not a big problem for me to explain Einstein's relativity theory or the difficulties in designing the various cooling cycles of a nuclear power plant but in this respect my best guess is that some of my male and female fish got together and had some fun (sort of) wink.gif

3) "sacking" the plants jap.gif what kind of fabric would you suggest? doesn't it have to be tight woven that earth is not dissolved and "leaking"? unsure.gif

1. I'd leave them there they perform a useful job and are a nice fish in their own right. If they do start to try to suck on the fish they will not have much success anyway because the carp are faster and have a lot of space to move in. It's rare of them to do so anyway and I would guess more of an aquarium problem where fish are crowded.

2. Ok, thought you might have added some other fish. The Koi seem quite small to breed, but that shows that the fish are happy anyway.

3. Needs to be tight woven to keep that earth in, but it'll always allow water to pass through it so don't worry about it being too tight. About this grade should do it, hessian sacking.

Useful webage

[Jai Dee]

Where did you buy your sucker fish (Plecostomus) Dr. Naam?

If they happily co-existed with the Koi I think I'd like to try them in my pond as well.

BTW, hunted all over Pattaya last weekend and only found 4 surface type aquatic plants at a nursery on highway 36.

I'll head down to Ban Chang/Rayong way this weekend to gee if I can find some there.

As an alternative to hessian sacking which isn't common here in Thailand, you could try some of those plastic woven sacks that potting mix comes in.

[Naam]

Where did you buy your sucker fish (Plecostomus) Dr. Naam?

If they happily co-existed with the Koi I think I'd like to try them in my pond as well.

i bought them in (i think it's) Third Road in a big shop which sells mostly fish and some birds. from Sattahip on Sukumvit turn left Thepprasit and right when Thepprasit ends. drive till fly-over and turn right. after ~500m make a u-turn when you see the shop on your right.

the "Suckers" do not bother the Kois and vice versa. in fact the fish form separated "herds" away from each other. Suckers are on the bottom or sucking the walls and hardly moving, Kois cruise just below the surface.

that's the good news. the bad news is that my freshly cleaned and filled pond was yesterday crystal clear but green algae have formed over night

[Naam]

hunted all over Pattaya last weekend and only found 4 surface type aquatic plants at a nursery on highway 36.

more specific please Jai Dee. did the nursery have ample supply?

i was thinking of the sacks you suggested too although i don't know where to get empty ones.

[Jai Dee]

hunted all over Pattaya last weekend and only found 4 surface type aquatic plants at a nursery on highway 36.

more specific please Jai Dee. did the nursery have ample supply?

i was thinking of the sacks you suggested too although i don't know where to get empty ones.

The nursery was on the left on 36 just as you come out from the Sukhumvit overpass (turning right from Sukhumvit onto 36).

And no... the lady only had 4 solitary plants in a small water feature, which she gave us for free.

We felt obliged to buy some other garden plants from her because she was so nice.... which we did.

Not sure where you could get those sacks... apart from asking at one of the larger nurseries.

Just a thought... perhaps if you erected a large shadecloth "sail" over your pond to keep the sunlight down might assist in the slow return of the algae... at least until you get good plant coverage.

These plants seem to be in short supply.

[Big Guy]

The sucker catfish will be available at any aquarium shop at 2-3inches long as they are the fish that is used to clean the glass. dont be worried about the size as they grow really rapidly in a pond with an adequate supply of algae to eat

[Richb2004v2]

There is a fish shop in Ban Chang that sells some pond plants. I am thinking of plants that are in pots but that have large round’ish leaves that spread out on the surface.

The shop is left at the first traffic lights in Ban Chang, coming in from Sattahip. This is a strip with a lot of girlie bars on it. The shop is actually behind these bars. It’s difficult to give exact directions, but there’s not that many Soi behind there so you should find it. The shop also sell various fish.

I'm not sure that it's exactley what you want, but if your in Ban Chang anyway it may be worth checking.

[Jai Dee]

Thanks for the tip Richb2004v2.

I'll check it out on the weekend.

[Naam]

Just a thought... perhaps if you erected a large shadecloth "sail" over your pond to keep the sunlight down might assist in the slow return of the algae... at least until you get good plant coverage.

technically nearly impossible because of the size. and mind you... algae came back OVER NIGHT. no sun and no moon

driver got a few floating plants from some standing water somewhere in the wilderness. Kois are happily chopping off the tiny roots of the plants

nex step... i haven't got too many ideas, but definitely not a bio-filter for several hundred thousand Baht and additional electricity cost exceeding the salaries of our three employees. as i mentioned already, there's a limit to everything.

thinking of reducing the surface area of the pond by 90% to a mere 10-12 m² which might help (if i find a contractor to do the job).

[bkkmadness]

Section off the plants in some way so the Koi can't get to them. Let them grow to be a nice number and then you can let them out to the main pond. Algae is building up because you have just filled your pond with tap water which is full of nitrate and the algae is feeding off it. Get those plants growing and it'll start to use all the nitrate itself. I did say you'll need to be patient and let the pond find a balance, it can take a while, months even.

[Jai Dee]

Remember I told you I drained my pond and put a handfull of copper sulphate in the residual 1-2" of water and scrubbed it all around? I use copper sulphate in the swimming pool.

Well, since then, I have refilled it, and no algae has returned yet. And the pond sees full sunlight all day. 2 weeks now...

May be an option?

One way to reduce the sunlight on the pond surface is to build a bridge over it... a simple wooden one with maybe a sunken section to put some potted plants in it is one type that I've seen used to good effect. The plants could be rotated as their flowering period finishes.

[Naam]

Remember I told you I drained my pond and put a handfull of copper sulphate in the residual 1-2" of water and scrubbed it all around? I use copper sulphate in the swimming pool.

Well, since then, I have refilled it, and no algae has returned yet. And the pond sees full sunlight all day. 2 weeks now...

what about your fish Jai Dee? did they like it? CuSO4 is quite toxic (if i remember correctly) and there must be quite some active residue as algae have not formed.

where did you buy copper sulphate?

[Naam]

Section off the plants in some way so the Koi can't get to them. Let them grow to be a nice number and then you can let them out to the main pond. Algae is building up because you have just filled your pond with tap water which is full of nitrate and the algae is feeding off it. Get those plants growing and it'll start to use all the nitrate itself. I did say you'll need to be patient and let the pond find a balance, it can take a while, months even.

i use my own deep well but have no idea about the nitrate content. pH of my well water is 5.8-6.0 but within 5 days pH went up to 8.2 (measured a minute ago).

i have been patient for one full year

[bkkmadness]

i have been patient for one full year

The very moment you change all the pond's water that patience needs to start again. You're pond is completely new now, let it settle.

As for Jai Dee's comments, copper can be used to solved numerous problems in the pond but you have to be very careful about the dosage or you will be end of with a pond o dead fish. Be extremely careful with any copper treatments please.

[Naam]

"The very moment you change all the pond's water that patience needs to start again"

ARRRGH!

[Jai Dee]

I have not re-introduced fish yet... as I said before, I plan on starting again at the bottom of the Darwinian ladder... simple plant life first, then introduce small fish, follwed by larger fish, followed eventually by Koi (I hope).

I checkout my pond last night... and there is some green algae forming again in one of the wells in the rock and concrete waterfall... so I suspect I haven't overdosed on the copper sulphate. It is available at any pool supply shop.

Tomorrow I will head off to Ban Chang and Rayong to check out all fish vendors and nurseries, in an attempt to buy more surface aquatic plants... and maybe try a few of those small sucker fish.

BKKmadness, as Dr.Naam's pH seems to fluctuate a lot, do you think that the addition of some weak acid or soda ash to balance the pH would be beneficial?

I've never had a fish pond before, so I don't know what effect the introduction of chemicals would have on on plants and fish.

I do know that my swimming pool is in perfect chemical condition.

[Naam]

BKKmadness, as Dr.Naam's pH seems to fluctuate a lot, do you think that the addition of some weak acid or soda ash to balance the pH would be beneficial?

pH does not really fluctuate but goes up in no time. partly because it takes a long time for concrete to cure, other reasons are unknown to me.

read a lot about algaecides in ponds yesterday and it seems appropriate doses of copper sulphate does not harm the fish. problem is obviously to "dose appropriately".

still waiting for your advice where to buy copper sulphate Jai Dee.

[Jai Dee]

still waiting for your advice where to buy copper sulphate Jai Dee.

Any pool supply shop Doc. (I did answer in the previous post).

I use Pattaya Home and Pool on third road.

[bkkmadness]

Having a pond with a pH of 8.2 is fine, the fish will have no problem with that as long as it's relatively stable and eventually it'll drop down a little anyway.