Digging My Pond

[xylophone]

Never have liked catfish for some reason, maybe it's because they are so ugly. Saw a programme regarding a British guy who had moved to France and was trying to entice fishermen from Britain to visit his property for a fishing holiday and camp beside his newly stocked lake.

The problem was that the few people that visited early on in the piece never caught anything, despite him having spent a fortune stocking the lake with fish. The locals told him about the rumour of a very large fish in the lake which would eat everything. So he drained the lake after one unsuccessful season, and found the biggest catfish you could ever imagine, wallowing around in the mud. Once that was removed, things were back on track.

Won't the catfish eat the other fish in the lake?????

[ozzydom]

Never have liked catfish for some reason, maybe it's because they are so ugly. Saw a programme regarding a British guy who had moved to France and was trying to entice fishermen from Britain to visit his property for a fishing holiday and camp beside his newly stocked lake.

The problem was that the few people that visited early on in the piece never caught anything, despite him having spent a fortune stocking the lake with fish. The locals told him about the rumour of a very large fish in the lake which would eat everything. So he drained the lake after one unsuccessful season, and found the biggest catfish you could ever imagine, wallowing around in the mud. Once that was removed, things were back on track.

Won't the catfish eat the other fish in the lake?????

Depends on the species ,some are carnivorous some omnivorous .

[ozzydom]

Hi DL

What is Kings Grass?

Don't make the mistake I made and let someone plant one of those Lotus lilies that you see growing in the water by the roadside.

It took over within months and was a b****r to get rid of.

Great thread, keep it coming

TBWG

TBWG, Kings Grass is probably better known by the name Vetiver, so named "Kings Grass" because of his initiatives with it around Thailand in the past.

Its a grass that has very deep roots and is used to stabilize sloping earth, like riverbanks, hillsides etc. Perfect to help keep my pond banks together and reduce any erosion.

I understand that it is available free of charge, but I am yet to find it locally.

Thanks for the advice on lillies. I would have done exactly that, if not for your and Ozzy's advice.

Just ask any local farmer where you can get some Ya Fat , most Government water impoundments and reservoirs use it for soil stabilisation.

[tftest]

looks great.. would you mind showing us how things have settled by now?

[basilic13]

Great thread indeed and beautiful pond!

I am actually about to do exactly the same, by end of August

My worry is that the soil of my land being very sandy, I won't have the chance to have the water level sipping up like seen on those pictures.

I might just end up then with a dry hole.

I heard about pond liners in order to have stable water level in the pond. I am trying to get information on how where to buy it, at what price and to what extent this can be set up in DYI manner.

Any help, shared experience and advice on this would be highly appreciated!

Thanks!

[ozzydom]

Great thread indeed and beautiful pond!

I am actually about to do exactly the same, by end of August

My worry is that the soil of my land being very sandy, I won't have the chance to have the water level sipping up like seen on those pictures.

I might just end up then with a dry hole.

I heard about pond liners in order to have stable water level in the pond. I am trying to get information on how where to buy it, at what price and to what extent this can be set up in DYI manner.

Any help, shared experience and advice on this would be highly appreciated!

Thanks!

The first step in your project would be to dig a few test holes at the boundaries of your proposed layout, you may well find that the sandy soil is not very deep,depending on your location it would be fairly unusual for the topsoil to be very deep (unless you are watefrontage ).

If you find a clay based soil not to deep , then you dont have a real problem as you can grade the topsoil to a long angle to be grassed and the top of the clay base can be your new top edge.

Your excavation contractor will want an idea of what he will encounter anyway.

[basilic13]

Ozzy thanks for the advice indeed!

the land is in the chaam area... about 10 km from the sea towards the mountaints.. do you think how deep sandy top layer would be reasonable to expect?

approximately how deep you think a pond should be? originally I was thinking about 1 m, but from what i have read here, i think 2 m should rather be more realistic.

any feed back is highly appreciated...

[ozzydom]

Ozzy thanks for the advice indeed!

the land is in the chaam area... about 10 km from the sea towards the mountaints.. do you think how deep sandy top layer would be reasonable to expect?

approximately how deep you think a pond should be? originally I was thinking about 1 m, but from what i have read here, i think 2 m should rather be more realistic.

any feed back is highly appreciated...

Test holes is the only way to accurately check the proposed site , a couple of willing strong backed workers and a thousand baht should reveal all.

What was the land originally used for?? if it was paddy ,I would not expect the sand to be very deep.

1.5 - 2 metres is a good depth as a certain amount of silting up will occur.

What will be your water source ?? seepage or from local source like a Klong ??

A test hole will also help you ascertain the amount of water available through seepage, if you find a clay base not to deep ,go down into it a couple of feet ,then see if water enters and if it holds ok . A few baht spent this way will give an indication of the sites suitability for a pond and save a lot of future disappointment.

If you have success in finding a suitable base,(sub soil ), an idea is to strip the sandy topsoil from the proposed site + 12 foot all round and stockpile this material to be used to form and top dress your banks after the pond is dug, this way you can get a nice long angle grassed slope right to your finished water level.

But best to put the horse in front of the cart and get you test holes dug first up.

[Macx]

Won't the catfish eat the other fish in the lake?????

Depends on the species ,some are carnivorous some omnivorous .

I have a 20mx40m pond. It originally had maybe 3 resident pla chon, around 20cm size. With the first rain this year, the in-laws told me a bunch of pla chon and some other fish hopped out of the lake and "walked" four meters and hopped into my pond. So, I'm not exactly sure what's in it now.

Anyhow, three months ago I stocked it with 200 pla nin fingerlings (after reading some of your other posts, Ozzy). I was planing on raising just that for the bbq since the water is very murky/cloudy with clay soil runoff from the new foundation fill next to the pond (where I'm planning to build a little bungalow).

Well, two months ago, the in-laws gifted me with 3000 fingerlings, several varieties of catfish, pla ja ra met and a couple others. They all went in when I wasn't around, and I didn't hear about the gift until about a week later when our stock of fishfood ran out and I was instructed to buy more, a lot more.

Another week, and the fish start dying in droves--as I said they would.

I think the fish stopped dying and floating to the top about a month ago. The water is still as murky and creamy beige/orange as ever. I've planted Ya Fat, lemongrass and some other stuff around the pond, but it will probably take a year before all the bare soil will be covered.

But, now, the pla nin, which I like to bbq, has all but disappeared from the pond, most likely having been eaten by the pla chon, catfish, or whatever. BTW, the pla ja ra met seem to be growing the fastest, and the catfish seem to be the most populous (catfish are my least favorite). Just looking at the surface activity during feeding time, I'm guessing there are around 500-1000 fish in the pond--not sure. Way more fish than I wanted and way more than my pond can probably handle.

What to do?

Should I just raise this lot and add fully grown pla nin into the mix?

How can I get rid of some of those catfish?

Should I toss in 1 Amazon Peacock Bass and let it thin out the pond?

Thanks!

[basilic13]

Thanks Ozzy...

your advices are very much appreciated and I will definitely follow them

The land is for now a cashew tree / mango tree orchard with the neighbors' land used to grow eucalyptus.

Does that give you any indication on the nature of the soil that may be below ?

Thanks

[ozzydom]

Won't the catfish eat the other fish in the lake?????

Depends on the species ,some are carnivorous some omnivorous .

I have a 20mx40m pond. It originally had maybe 3 resident pla chon, around 20cm size. With the first rain this year, the in-laws told me a bunch of pla chon and some other fish hopped out of the lake and "walked" four meters and hopped into my pond. So, I'm not exactly sure what's in it now.

Anyhow, three months ago I stocked it with 200 pla nin fingerlings (after reading some of your other posts, Ozzy). I was planing on raising just that for the bbq since the water is very murky/cloudy with clay soil runoff from the new foundation fill next to the pond (where I'm planning to build a little bungalow).

Well, two months ago, the in-laws gifted me with 3000 fingerlings, several varieties of catfish, pla ja ra met and a couple others. They all went in when I wasn't around, and I didn't hear about the gift until about a week later when our stock of fishfood ran out and I was instructed to buy more, a lot more.

Another week, and the fish start dying in droves--as I said they would.

I think the fish stopped dying and floating to the top about a month ago. The water is still as murky and creamy beige/orange as ever. I've planted Ya Fat, lemongrass and some other stuff around the pond, but it will probably take a year before all the bare soil will be covered.

But, now, the pla nin, which I like to bbq, has all but disappeared from the pond, most likely having been eaten by the pla chon, catfish, or whatever. BTW, the pla ja ra met seem to be growing the fastest, and the catfish seem to be the most populous (catfish are my least favorite). Just looking at the surface activity during feeding time, I'm guessing there are around 500-1000 fish in the pond--not sure. Way more fish than I wanted and way more than my pond can probably handle.

What to do?

Should I just raise this lot and add fully grown pla nin into the mix?

How can I get rid of some of those catfish?

Should I toss in 1 Amazon Peacock Bass and let it thin out the pond?

Thanks!

Jeez Macx , sounds like a mess, cats require lots of expensive feed and 500-1000 is not worth buggaring about with IMO,even if you grow them to minimum market size they are only worth a pittance.

I would in your position , be tempted to pump down and get a local to take the lot off your hands for whatever you can get then then poison and treat the pond leave it for a few weeks and refill ,then start again .

You will have to take control of the pond and its workings. Thais are notorious for overstocking , even my T/W who knows better will toss 7000 fingerlings in a rai pond after I have stipulated 1500, simply because she reckons more is better.

You will always get a few uninvited Pla Chon wander in during the wet but normally they do little harm and grow pretty quickly , great for gifts to workers for that little extra effort

[Macx]

I can't wait to see their faces when I tell them what the pro advises

Thanks, Ozzy.

It's sorta what I was expecting (minus the poison bit).

It's still raining where we are so I guess I'll give it a few weeks. Some of the catfish are almost hand-length. I'll let them use up the feed. By then, I'm sure the in-laws will use them for soups

Thanks!

[TBWG]

Great thread indeed and beautiful pond!

I am actually about to do exactly the same, by end of August

My worry is that the soil of my land being very sandy, I won't have the chance to have the water level sipping up like seen on those pictures.

I might just end up then with a dry hole.

I heard about pond liners in order to have stable water level in the pond. I am trying to get information on how where to buy it, at what price and to what extent this can be set up in DYI manner.

Any help, shared experience and advice on this would be highly appreciated!

Thanks!

Hi

I found a good guide as to whether a pond will hold water is just to look at ponds in the vicinity, if they are OK good chance yours will, if there aren't any ponds in the area its for a good reason!

Then, liner is only way to go, but expect that would be hard work for any reasonable size pond.

TBWG

[ozzydom]

I can't wait to see their faces when I tell them what the pro advises

Thanks, Ozzy.

It's sorta what I was expecting (minus the poison bit).

It's still raining where we are so I guess I'll give it a few weeks. Some of the catfish are almost hand-length. I'll let them use up the feed. By then, I'm sure the in-laws will use them for soups

Thanks!

The "poison" for want of a better word , that I use is not actually a poison. It is the dried and shredded bark from a local tree that when sprinkled in the water ,depletes the oxygen and kills any small fishes left after pumping out and harvesting. Its effects are very short lived .

Because we top up from a Klong ,we get all sorts of foreign critters find their way into the ponds which for health and welfare of our main crop fish I prefer to eradicate if possible .

As a side note we accidentally introduced a small fish from down south with a shipment of fry, they look like guppies and the local fisheries officers call them Taiwon fish, well they are live bearers and breed like proverbial blow flies , we ended up with millions of them competing with the Pla Nin for their food .

T/W experimented with them and found that bbq,ed in a banana leaf with lemon grass, lime leaf and a little fish sauce the locals love them ,so a mistake ended up being a nice little earner on the side.

[basilic13]

Thanks TBWG,

but would you have any idea where to buy the liner?

I looked on the internet and around here and although everybody talks about it, I couldn't find any reference or company name selling the stuff in Thailand (only in the US).

Thanks

[DLock]

Pond hasn't really gained much water since it was dug and unfortunately no rain to help. But it has settled and is not the muddy brown. It's kind of a clear brown...if that makes sense.

So, tomorrow, I'll start pumping from the small creek next to the property just to see if it holds water beyond the water table level. Based on Ozzy's comments above, I might add a small filter to keep out critters.

Bought 15 clay pots to plant the water lilies and I'll just wait till its fuller before I add them.

Still waiting on the small macro to level out some parts of the bank, so no planting yet, but have found a supplier of Ya Fak, and will also plant lemongrass. Trying to find a hardy grass that spreads well...any one have any ideas?

A little erosion at the water level into the banks that were not sloped enough, just as Ozzy predicted. Hopefully raising the water level will stop that happening so low down.

[DLock]

Finally manged to get the Ya Faek sourced and planted, in between heavy rain and a smaller Macro (3,500 baht per day) levelling out the areas around the pond ready for planting.

I found a supplier in Chiang Rai who supplied Ya Faek for 1baht per plant, and he planted them for that as well. I read many posts say that Ya Faek is free, but I could not find any locally.

The supplier advised that I plant 1 plant every 10 cm on the top of the path and then 2 plants together, also 10cm apart at the edge of the pond.

You can see some of the early erosion from the heavy rain. Since then I have angled the land above the pond away from the pond to reduce erosion and the amount of dirty water that would flow in after rain. I will lay grass on some of the bigger dirt areas to stablise the dirt and improve its appearance.

Have deliberately pumped water out of the pond as the small Macro has to finish raising the bank of one end - the last end we dug which by then was very muddy and hard to build up. It also subsided a bit so that needs to be raised.

I bought a total of 6,000 plants, of which 1,000 are spare - as I expect some will not survive the rain and erosion and that I will have to plant again.

Have purchased 30 clay pots (25 baht each) that will I will put the water lilies into when the Macro has finished.

[ozzydom]

Just one small observation mate, I dont know if it is an optical illusion or not ,but those bank angles look extremely steep. anything less than 5-1 and erosion is a problem .

[littlebigboss]

Ozzydom, as you seem to be the reference here for everything that is pond related, I've some more question for you.

On this picture, you can see all the problems we have with our ponds.

First, related to your last post, you can see that nothing grows on the bank. Is it because the angle is too steep ?

Then you can see the two other problems I mentioned in an other thread : the reeds on the bottom left of the pictures and the algae. We bought a little boat to harvest the algae as the pond is quite deep but to hand pick the reeds (your advise) is definitively not an easy task.

A bonus question : I really don't know what the landscaper had in mind when he designed the lawn but those steps with slope at 45 degree are definitively not easy to maintain, any suggestion for a lawnmower ? (at the moment, we do it with a bush cutter !!!)

[mellow1]

^ Tilapia will eat the the algae.

[littlebigboss]

^ Tilapia will eat the the algae.

I didn't know what it was, so I checked Wiki : "Tilapia serve as biological controls for several aquatic plant problems. They prefer a floating aquatic plant, duckweed (Lemna sp.), and will eat some filamentous alga.^[13] In Kenya tilapia help control mosquitoes which cause malaria. They consume mosquito larvae, which reduces the numbers of adult female mosquitoes, the vector of the disease (Petr 2000). Negative effects may outweigh these benefits and cause Tilapia to be considered an invasive species."

If they can help us to get rid of the mosquitoes and the algae, it could be a good solution. We can even make a profit from them (Tilapia is the third most important fish in aquaculture after carps and salmonids, from Wiki). Regarding the negative effects mentioned, any information related to Tilapia in Thailand ?

[ozzydom]

Ozzydom, as you seem to be the reference here for everything that is pond related, I've some more question for you.

On this picture, you can see all the problems we have with our ponds.

First, related to your last post, you can see that nothing grows on the bank. Is it because the angle is too steep ?

Then you can see the two other problems I mentioned in an other thread : the reeds on the bottom left of the pictures and the algae. We bought a little boat to harvest the algae as the pond is quite deep but to hand pick the reeds (your advise) is definitively not an easy task.

A bonus question : I really don't know what the landscaper had in mind when he designed the lawn but those steps with slope at 45 degree are definitively not easy to maintain, any suggestion for a lawnmower ? (at the moment, we do it with a bush cutter !!!)

lbb,you answered your own question re the lack of growth on the bank, the bank looks near vertical and so will not hold moisture, as long as erosion is not a problem dont worry about it .

You would need to put a longer taper on that section to get grass established.

Rushes are a great environmental addition as they provide habitat and protection for many species including birds , that is until they get out of hand,one way to keep them to a manageable quantity is to just noose a rope around the foliage and pull excess clumps out with a tractor.

The best way to handle the algae is to eliminate its food source (nitrates and phosphorous ) a small amount of algae is not a great problem ,when you get a large bloom it can be a problem as algae puts oxygen into the water during daylight but removes oxygen during darkness thus deprives your fish of oxygen.

As mentioned by another poster, Tilapia do eat algae ,but are very prone to low oxy conditions so if you see Tilapia near the surface gulping about sun up then low oxygen is a problem.

A hover type lawnmower is what you need for those terraces, you mow from the level of each embankment using a rope on the handle. You just keep lowering the mower for each cut and walk it from one end to the other,or uses two ropes and two men and swing the mower, very large terraced and grassed abutments on highways are done this way in Oz,many are up to 60degee slope

[ozzydom]

^ Tilapia will eat the the algae.

I didn't know what it was, so I checked Wiki : "Tilapia serve as biological controls for several aquatic plant problems. They prefer a floating aquatic plant, duckweed (Lemna sp.), and will eat some filamentous alga.^[13] In Kenya tilapia help control mosquitoes which cause malaria. They consume mosquito larvae, which reduces the numbers of adult female mosquitoes, the vector of the disease (Petr 2000). Negative effects may outweigh these benefits and cause Tilapia to be considered an invasive species."

If they can help us to get rid of the mosquitoes and the algae, it could be a good solution. We can even make a profit from them (Tilapia is the third most important fish in aquaculture after carps and salmonids, from Wiki). Regarding the negative effects mentioned, any information related to Tilapia in Thailand ?

Tilapia are grown in ponds and net cages in major waterways here in Thailand, many escape but have not been a problem as they are grown in heavily nitrated water and live on primarily phytoplankton they do not thrive in rivers unless fed propriety foods, plus there are many native carnivorous species to keep them in check.

[DLock]

Ozzy,

No optical illusion. That end of the pond is the bit we dug first, before your advice, so yes, it is about 45 degrees and already seeing some erosion.

The other end is about 3:1 or so, and shows no signs of erosion.

I build the pond smaller than initial plans for exactly that reason, and it looks like it was the right move.

Hoping that when the Macro has finished and the pond is at capacity, the erosion on the banks are less.

Appreciate the comments.

[tftest]

Im sorry.. not so sorry.. for bumping this thread again. I really like this one..

[GarryP]

Im sorry.. not so sorry.. for bumping this thread again. I really like this one..

Me too. DLock shouldn't have any problem filling the pond with all that rain in the north.

Edited September 17, 2009 by GarryP

[DLock]

I will post some pictures soon of hows its going.

Ozzy was right about the sloping sides. The first side I dug was too steep and combined with some sandy layers, there has been some erosion on that side. The rest have no issues except som rainwater tracks.

I added some sample water plants to see how they would take, from some lilies (in pots), reeds and some other plant and they all have done well, so next week I will add a whole lot more.

Then I added fish. I did as much research as I could and listened to Ozzy's advice. I tried to contact the Govt fisheries department up in Chiang Mai, but all the numbers were old and didnt work. So, I went with a local breeder. He came over to look at the pond size. I asked him how many fish and said that I was considering about a "1 thousand"...he said "20". I said "20 fish?" and he said "no, 20 thousand". Clearly his goal of selling me as many fish clashed with my Sunday afternoon liesure ideas.

In the end I added 500 Pla Nin mixed sex, 500 Tab Tim (mixed), 500 Pla Duk. I had asked for Pla Sawai (striped catfish) and Pla Buek (Giant Mekong catfish) and the next day he turned up with 250 mixed. The fish ranged in size from about 3 inches for the catfish to 1 - 3 inches for the rest. He also brought around some bigger catfish, but I thought they might eat the smaller fish, so despite my impatience with wanting to fish...I'll wait. I am feeding them with a high protein fish food twice a day.

I added grass to the upper banks of about half the pond - both to soak up rain, and stabilise the earth. The first day I went to the market and ordered what I thought was 100sqm. It cam up to about 2/3rd of th eback of my pickup. We laid it that afternoon on a bed of topsoil. The next day I went to buy more and went to a different shop and asked for 100sqm. He said intimated that it would ride about 2 feet above the truck. I said "No, I bought yesterday, no problem". It was about as the grass tiles extended about 1 foot over the bed that I realised I was ripped off the day before.

A single grass tile is 1meter x 1/2 meter. Two tiles = 1 sqm. The day before, they had only given me 100 grass tiles = 50sqm, and I paid the meter price. I was annoyed but my wife knows what happens when I comfront people who rip me off - furniture gets rearranged. So, I shrgged it off and sure enough, when we laid it and measured it, it was twice as much as the day before.

Bought a 2,000 liter per minute pump and pump direct from the Klong to the pond. The level drops considerably every day, hinting that the water level is based on the water table, which fluctuates. Could get expensive in the dry season. Water color is still muddy brown and probably always will be.

The Ya Faek (kings grass) is shooting up well and I have placed a lot of lemon grass further back as a kind of boundary.

I did visit Dokmai Gardens in Chiang Mai and Eric took me around his gardens and gave great advice on what I should plant. It was a great day and I recommend anyone who wants to learn about and see the plants and get good advice, its a great afternoon.

So far its been fun and I have learnt a lot. Made a few mistakes, but hey...my title is accurate...I am an idiot without a clue on this, so I am stumbling through it.

[DLock]

I saw how many words I typed and realized that it was far too much to read and without pictures it didnt mean much. So, I got of my butt and took some pictures so you can see the progress.

Wish I'd taken pictures of the fish for reference, but that day was really heavy rain and slippery mud...

1. Lake as I walk down from the house. You can see the erosion on the other side of the pond

2. Newly grassed upper bank. Pathway with Ya Faek bordering. Very wet and mushy lately.

3. Closer look at some of the plants, obviously planted when water was lower. Interesting to see how they do.

4. The Klong. I am fortunate to have a klong that runs all year to draw fresh water from.

5. The new grass from the other end. Not ethe bamboo extension pipe from the klong pump.

[GarryP]

Coming along great. Just a thought. When you are out fishing in the mornings and evenings, mosquitoes may be a bother. As such it may be worth planting some "scented" lemon grass (ask your wife) instead of the ordinary stuff. It will really keep the mossies away. Some types of chrysanthemums also act as a repellant but I don't think they would look at all good in environment you have (sort of out of place if you get what I mean).

I feel you have overstocked the pond but then I know absolutely nothing about pond management and stocking fish.

I have a piece of land upcountry with a natural pond on it. Water in it all year round and I am thinking of expanding it and building a small resort type home adjacent to it. Somewhere to spend my vacations and cast my line.

Edited September 18, 2009 by GarryP

[DLock]

Coming along great. Just a thought. When you are out fishing in the mornings and evenings, mosquitoes may be a bother. As such it may be worth planting some "scented" lemon grass (ask your wife) instead of the ordinary stuff. It will really keep the mossies away. Some types of chrysanthemums also act as a repellant but I don't think they would look at all good in environment you have (sort of out of place if you get what I mean).

I feel you have overstocked the pond but then I know absolutely nothing about pond management and stocking fish.

I have a piece of land upcountry with a natural pond on it. Water in it all year round and I am thinking of expanding it and building a small resort type home adjacent to it. Somewhere to spend my vacations and cast my line.

Gary, I also think it may be overstocked, and hope Darwin's theory helps manage that process for me...but I'm sure a few weekends invitations to all the local farmers to catch whatever they can will help thin it out if it does get to crowded.

I'll take your advice on the scented lemongrass...hate mozzies.