A. Fish Environment / Environmental Requirements

WATER MANAGEMENT

Water temperature

All fishes have upper and lower temperature tolerance limits. When the temperature goes beyond the temperature tolerance limit of the fish, the effects are:

• abnormal metabolism resulting in poor growth, abnormal activities or stress
• poor response to supplemental feeds
• very poor feed conversion ratio

An ordinary thermometer or an equivalent device can be used to measure water temperature.
Tilapia nilotica can tolerate water temperature range of 14° - 42°C. However, for culture purposes, the ideal water temperature should range from 25°C to 30°C.

Hydrogen ion (pH) Concentration. The pH of the water determines its acidity or alkalinity. If the pH is between 0-6.0, the water is acidic, and if the pH is 7.0, it is neutral. Alkaline water has a pH of 8.0 -14. The ideal pH range of freshwater culture is 6.5 - 9.0.
The effect of the various pH value on fish is shown below:

pH Range	Effect
4 and below	Fish die because of acidity
4 - 5	No reproduction
5 - 6.5	Slow growth because of low fish food production
6.5 - 9.0	Fish thrive well and grow fast
11 and above	Fish die because of alkalinity

Ammonia. This is highly toxic to fish. the symptoms of ammonia toxicity in the fish are:

• spongy appearance of gill filaments
• presence of bloody gills
• excessive production of slime
• poor growth of fish

Dissolved Oxygen. All fishes, regardless of species and culture conditions, need oxygen for growth and survival. Lack of oxygen results in poor growth and outbreak of diseases or mortality. Generally, most warm water species need dissolved oxygen at a level of one part per million (ppm) for survival and about 3 ppm for comfort. Dissolved oxygen of 5 ppm is the most ideal for growth and is excellent in maintaining fish health. However, tilapia species can grow well at dissolved oxygen level of 1 - 3 ppm

Good water management prevents the occurrence of dissolved oxygen depletion. In order to maintain high dissolved oxygen level in the pond, do the following:

• Prevent the growth of unnecessary aquatic vegetation, such as "kangkong" over the pond surface. These plants shield the pond from sunlight and slow down photosynthetic activities of phytoplankton to produce oxygen.
• Follow the recommended stocking rate of the pond. Over-stocking leads to high oxygen consumption and possible oxygen depletion especially at night.
• Avoid giving excess feeds to the fish since unconsumed feeds pollute the pond water when they sink to the bottom and decay.

Some of the signs manifested by fish due to dissolved oxygen depletion in ponds are:

• Restlessness associated with abnormal closing or opening of the operculum.
• Gasping for air at the water surface
• The pond water becomes brownish to grayish and smells pungent

Turbidity. The presence or suspended solids in the water causes turbidity and muddiness of the water. Generally, suspended solids include sediment particles, organic matter like detritus, fecal materials and phytoplankton. Turbidity can be either an advantage or a disadvantage in fish culture. It is advantageous if it is caused by plankton. However, if the water is turbid due to minute solid particles, then this becomes a disadvantage because the sediment particles prevent photosynthesis. Turbid water has the following effects:

• suspended solids clog the gills of the fish or cause irritation on the gill filaments.
• heavy minute particles can bury eggs and larvae of organisms that live in the pond bottom.

pangatlong yugto

matapos malaman ang paggawa ng tanke, filter at iba't ibang kaalaman ukol sa tilapya makabubuting simulan na ang mga tips at paraan ng pag-aalaga.
Mula sa pagpili ng fry hanggang sa pagpaparami nito.

Tech check: Gawing Lalaki ang babae Tilapia

Ang mga lalaking tilapia ay mas mabilis lumaki at mas malalaking di-hamak kaysa mga babaeng tilapia. Ang mga lalaki ay karaniwang tumitimbang ng mula 600-800 gramo sa loob ng apat na buwan, at maari pa itong lumaki pa kung hahayaan, ngunit ang mga babaeng tilapia ay umaabot lang ng 150 gramo sa ganoon ding panahon.

Palibhasa mabilis manganak ang babaeng tilapia, ang sobrang pagdami ng isda sa palaisdaan ay nagpapabansot sa mga isda, at marami ang namamatay.

Kung haluhalo ang babae at lalaki, hindi pare-pareho ang paglaki ng mga isda kapag panahon na ng pag-aani sa kanila.

Mga Kailangan:

1. pinong hapa (binaliktad na kulambo)

2. Formula SRT-95 (hormone)

Paraan ng Paggawa:

1. Isalin agad sa hapa (sa palaisdaan) ang mga napipisa pa lamang na isda mula sa bunganga ng inahing tilapia.

2. Pakainin agad ng pormulasyon na hormone ang mga maliliit.

3. Gawin ito sa loob ng 21 araw. Ang isang kilong hormone ay makapagpapakain ng 6,000 na semilyang isda.

Ang porsiyenton ng isdang nagbabago ang kasarian kapag pinakain ng hormone na ito ay mga 95-99%.

Pagkalipas ng sampung (10) araw, hindi na mapag-iiba ang kasarian ng mga isda kahit pakainin ng hormone.

Ang karunungang ito at natuklasan ni Dr. Rafael Guerrero ng Central Luzon State University noon pang 1977, na ibinase sa kanyang tesis sa pagkadoktorato niya sa Auburn University. Hindi niya ipinagdamot ang karunungang ito bagkus ibinigay niya sa taong bayan, sa ngayon ay pinakikinabangan. Nagbigay ito sa kanya ng karangalang "TOYM" Award at ng S & T IBM Award noong 1987.

Ikalawang yugto: Basihang kaalaman ukol sa tilapya

Ikalawang yugto- Kaalaman ukol sa isdang tilapya


Ang tilapya ay unang dinala sa Pilipinas noong 1972, naging mabilis ang pagsikat nito dahil sa dali nitong padamihin, mabilis na paglaki, pagiging masarap, pagiging malakas ang resistensya sa sakit, at ang pag-angkop nito sa iba't ibang uri ng klima, temperatura at alat.

URI NG TILAPYA

Genus Tilapia (Substrate spawners)
Both parents guard, protect, aerate the breed, and help move clutch to different nest sites. Fry at first feeding are 4-5 mm and show feeble swimming ability. Fry survival relatively low.

Genus Sarotherodon (Paternal/biparental)
Both parents stay close to each other. Eggs and fry brooded in oral cavity up until they are ready for release. Brood may not be collected once released. Fry are between 7-9 mm at first breeding, well developed fins for swimming. Fry survival high.

Genus Oreochromis (Maternal)
Female solely involve in brood care. After spawning, female leaves nest to rear her clutch in safety. Fry brooded up until free swimming. There is an extended period of care during which fry seek shelter in buccal cavity for safety. First feeders have well-developed fins for swimming. Fry survival high.

PAGKILATIS NG KASARIAN

madali ang pagkilala kung ang tilapya ay babae o lalaki, Ang lalaki ay may dalawang butas just in front of the anal fin. at ang babae ay may tatlong butas. Kung ang isda ay 15 gramo na maaari na itong makita.

Sex identification of tilapia is relatively simple. The male has two openings just in front of the anal fin. The large opening is the anus and the smaller opening at the tip is the urogenital pore. The female has three openings: the anus, the genital pore, and the urinary pore. The genital papilla is usually smaller in the female. Tilapia can be sexed when it has attained the weight of 15 grams. Application of ink or dark dyes to the papillae may increase the accuracy of sexing and may allow sexing of smaller fish. By rubbing ink along the papillae of the tilapia, sexes can be readily distinguished.

PAGPUPUNLA/ PAGPAPARAMI

The Nile tilapia is a mouth-brooder. The male establishes a territory and builds a round nest in the pond bottom. (Usually the diameter of a nest is 30 to 60 centimeters. The size of the nest is correlated to the size of the male). The female enters the nest and lays the eggs. The eggs are fertilized by the male. The female then collects and incubates the eggs in her mouth. The eggs are yellow in color. Eggs hatch in about five to seven days. After hatching the fry remain in the mouth of the female for another four to seven days. The fry begin to swim freely in schools, but may return to the mouth of the mother when threatened. Females do not feed during incubation or the brooding period.

Females spawn every four to six weeks, but may spawn sooner if the eggs are removed. The number of eggs per spawning is related to the size of the female. A female of about 100 grams may produce approximately 100 eggs per spawning while a female of about 100 to 600 grams can produce approximately 1,000 to 1,500 or more eggs per spawning.

Siklo ng produksyon ng tilapia

UNANG YUGTO: DISENYO NG TANKE AT FILTER SYSTEM

Narito ang pagsasalarawan ng itsura ng tanke at filter system
Pag-aralan kung paano idenisenyo ang tankeng ito.
Top View



Side View


Constructing a pond

Picture of where to locate a pond bottom drain

Dami ng bottom drain pipe:

A rule of thumb is one bottom drain for the first 15 000l and then one drain for every 10 000 - 15 000 l thereafter. Of course, the size of your pond will have a lot to do with this - as will the flow rate you want through your filter systems. If you turn your pond water over every two hours, and the size is 50 000l you will need 25 000l per hour coming from your bottom drains.

II: A Filter system design: Side View



Settlement Chamber / Tiningan



Litrato ng filter system base sa disenyo sa itaas:

Note that the white pipe is the stand pipe for the settlement chamber. So bottom right is the settelement chamber flowing to bottom left which is where mechanical filtration takes place. Then the third chamber which is a bio-filter chamber - top left - feeds the last chamber (top right) which is where the pump sucks clean water to return to the pond.

Pond water will flow from the bottom drains of the pond up the pipes in the direction of the red arrow as shown.

An ideal settlement chamber will be sloped from shallow to deep. The bottom drains will all face upwards and be located in the deep end of the settlement chamber, whilst at the opposite side on the shallow end of the chamber the exit pipe that feeds the primary mechanical filter stage will be located.

Being located higher than the bottom drain pipes increases the likelihood of the solids entering into the settlement chamber being collected in the deep end.

And YES, this does mean you need a waste flush valve located somewhere near the deep end of the settlement chamber so that you can flush all these nasty solids straight out and off to waste.

BUT:

If the waste valve on the settlement chamber is open, the water from the pond will simply continue to pour into the chamber from the bottom drains...

Yes, it will. Unless you block these pipes off it will not be possible to empty the settlement chamber without having the bottom drain pipes filling it continually. This is an important point to keep in mind!

Now, can you see why we want the bottom drains facing upwards?

You can block these off very easily using what is called a stand pipe. This is simply a long pipe that 'stand's inside the bottom drain pipe - it needs to be a flush fit to work properly - your Koi pond builder will know how to do this. So if you have 5 bottom drains, you will need five 'stand pipes'.

With the stand pipes in place, you can empty the settlement chamber. This allows you to get rid of all the muck in the chamber quite easily as it flushes out along with the water in the chamber.

Removing the stand pipes has an interesting effect. Because the chamber is now empty, water will literally rush in from the pond through the bottom drain pipes, at a rapid rate indeed. This sudden surge of water through the bottom drain pipes has the effect of a mini flood, sucking all the solid debris in the pipe with tremendous force and depositing it into the settlement chamber from where it can be flushed to waste. Voila! Settlement chamber is cleaned, and the bottom drain pipework is also purged of excess solid waste.

FILTER SYSTEM PARA SA MGA BAGUHAN.

Ang sumusunod ang nagpapaliwanag kung anong dapat ilagay sa bawat chamber ng filter system at mga alternatibong gamit na matatagpuan sa mga rural na lugar.

1) As you can see Ammonia is produced by a) fish respiration, excretion and constant urinating. b) plants decomposing c) excess food (this is the biggest contributer).

so the next steps are done by the process of our filters.

IKALAWANG KUWARTO: MECHANICAL FILTERS:

Pagkatapos dumaan sa settlement chambers ang sunod naman ay ang mechanical filters:(ang artikulo ukol sa settlement chambers ay sa ibang post)

2) Within this chamber we have brushes and/or nets. We need to get rid of some of these ammonia producing particles. So we have a mechanical filter. This will catch excretion and waste food and also parts of decomposing plants. At this stage Ammonia will still be present in the water. Please note that Ammonia is highly toxic, even in small concentrations.

Maaari ring gamitin ang nga sumusunod na bagay: graba, bunot ng niyog, Uling (wag pipinuhin) Seashells Atbp na puwedeng gawing salaan siguraduhin lang na walang lason ito.
Tandaan: mas makabubuting lagyan din ito ng drain pipe na may valve upang madali ang paglilinins at madaling tanggalin ang mga duming nakatambak:

Tandaan: isupot sa mga netbags ang mga bagay na ilalagay sa chamber na ito, sa ganitong paraan madali ang paglilinis.

IKATLONG KUWARTO : BIOFILTERS:

3) The next stage is the bio filter. This will consist of Flocor, Stinted glass, Japanese matting etc. the higher the surface area, the better. This filter must be covered to protect from sunlight. Within this filter and on the filter media live bacteria called Nitrosomonas. These bacteria are aerobic which means they require oxygen to survive. So it is essential that you provide these guys with as much Oxygen as possible via an airline (i.e air pump with air stone). They also need food, their favourite food is Ammonia. So, by eating Ammonia (NH3) and breathing Oxygen (O2), they excrete Nitrite (NO2).

Also within this filter chamber you will have bacteria called Nitrobacter. These guys are also aerobic so they also need a constant supply of oxygen. Unlike the Nitrosomonas, the Nitobacter eat Nitrite, they excrete Nitrates.

Mga alternatibong gamit: coconut shells, bao, balat ng kahoy(barks), oyster shells,

ganito ang itsura ng magandang medium sa pagpapalago ng bakterya sa bio filter. Kung may makikita na bagay na nakakahawig nito ang disenyo mas maganda.

Kung gagamit ng bao o kahoy, kailangang palitan ito minsan sa isang taon.At hindi sabay sabay ang pagpapalit.!!!! Alalahanin ang mga bakteryang nandito. Ito ay kailangang hindi naaarawan, may taklob lagi.

Ang biofilter ay hindi nililinis, hindi hinuhugasan mas maigi na paminsan-minsan ito ay pinapahanginan sa pamamagitan ng air pump upang maging optimal ang buhay ng bacteria dito.

Sa unang pag-setset up nito, kailangan lagyan ng nitrifying bacteria ang chamber na ito. Ito ay mabibili sa mga aquarium shops, upang mas madali ang pagdami ng bakteryang ito, partikular na ang bakteryang Nitrobacter. Pagkatapos dumadami na ito ng kusa.

Puwede ring magtanong sa may mga fish pond na may bio filter, dito maaari ring manghiram ng ilang medium na puwedeng ilagay sa chamber na ito, sa loob ng 2-4 na linggo ay gumagana na ang sariling bio-filter.

IKAAPAT NA KUWARTO: PUMP CHAMBER

5) The next chamber should be a pump chamber or a vegetation chamber. We know now that the main element in this chamber will be Nitrates. So we need to get rid of these.

5a) If this is a pump chamber then this will consist of some sort of PH buffer material (in netted sacks) i.e. Coral chips, Oyster shells etc. and your pump(s). From here you have two options: a) You need to pump the water back to the pond via a waterfall that consist of plants. These plants use Nitrates as a form of fertiliser, and in return they supply that water with Oxygen. b) You need to pump this water back to the pond, but some of this water should be diverted via a trickle tower which will remove Nitrates from the water.

5b) If this is a vegetation chamber, unlike the other chambers, this should not be covered as most plants need sunlight to live. In here you need water plants that produce lots of leaves. The more leaves the better. I would recommend that at the exit of this chamber you have another row of brushes or netting, to stop large particles of debris feeding back into your pumps. This chamber will eat the Nitrates and produce oxygen. After this chamber you should have your pump chamber, see section 5a) for more info.

Ang pinakahuli ay ang tinatawag na pump chamber maaaring lagyan ng halamang nabubuhay sa tubig. i.e gabi, sa ganitong paraan mababawasan ang nitrate concentrate na bumabalik sa fish pond. Puwede rin naman lagyan ng talaba, or sea shells

at panghuling tip upang madaling maglinis sakali mang lilinis ito:

Each chamber should have at least one 2-4in. drain outlet with standpipe. This is to facilitate removal of accumulated debris during filter maintenance.