How to Breed Peacock Gudgeons
To breed peacock gudgeons, start by placing 1 male and 1 female in a tank together, and place a piece of PVC pipe in the tank with them so the female has a shelter to lay eggs in. Then, wait around 2-3 weeks for the fish to breed. Once the female lays eggs in the pipe, wait 6-7 days for the eggs to hatch, and then immediately transfer the newborn fry to a separate tank so they don't get eaten.
Add 3 in (7.6 cm) of dark substrate to a 5 US gal (19 L) covered tank. You can find a variety of substrates and tanks at pet supply stores or online. Dark gravel or sand is ideal and any regular aquarium of this size works well. Pour the substrate directly into the tank and spread it out evenly across the base to create a smooth layer. Plant 3-4 live Java ferns in the substrate. These plants are great for peacock gudgeon fry as they provide the first food. Dig a small hole approximately 1 in (2.5 cm) deep in the substrate for each plant. Try to space the plants around the tank. Java ferns are sold in pet supply stores or online. Java moss is also a good option. The fry feed on tiny organisms called infusoria which live in Java ferns and moss. Place an airstone in the fry tank. Airstones are small and inexpensive pieces of aquarium furniture that are designed to add dissolved oxygen to the water. Place the airstone anywhere on the substrate. The bubbles it creates keeps the water moving which helps the fry to survive. Fill up the tank with dechlorinated tap water. Read the manufacturer's directions to find how much dechlorinator to treat the tap water with. Pour the water directly into the tank and add the specified number of dechlorinator drops. Practice keeping the cover on the tank, as peacock gudgeons can jump! Install a heater to keep the water temperature between 76–80 °F (24–27 °C). Follow the manufacturer's directions carefully and mount the heater to an inside wall of the tank using either the mounting bracket or suction cups. Adjust the temperature dial and then turn the heater on. Check the temperature after 24 hours using a thermometer to make sure that the heater works properly. Make sure that the heater isn't in contact with any plants in the tank. Peacock gudgeons need warm water to survive. Check that the pH is 6.5-7.5 and the water hardness is 5-10 dGH. Use a master water quality testing kit and place a sample of the tank water in the test tube. Add each testing solution and match the color of the aquarium water to the color chart. pH and water hardness are the most important parameters for peacock gudgeons. Treat the water if necessary using water quality adjustment products. If the testing indicates that changes to the quality need to be made, purchase adjustment products from a pet supply store. There are many products available that safely alter parameters like pH, water hardness, and ammonia. Simply add the specified amount of the product to the tank water and test the water quality again after 24 hours. Get a breeding pair of peacock gudgeons. Make sure that you have 1 male and 1 female. Females have a black line across the edges of their fins, whereas males don't. Also, males have rounder heads and females have more pointed and angular heads. There is no specific season for breeding peacock gudgeons and the fish tend to start breeding within 2-3 weeks of being put together. Peacock gudgeons tend to start breeding from 6-8 months old. The female is ready to spawn when her abdomen is bright yellow. The breeding pair don't need to be alone, as they are happy with tankmates. Place a PVC pipe "cave" into the adult tank. Cut a 7 in (18 cm) long, ⁄ 2  in (1.3 cm) wide piece of PVC piping and place it directly on the tank substrate. This creates a cave where the female peacock gudgeon will lay eggs. Alternatively, you can use a wooden aquarium cave. Observe the tank to see the peacock gudgeons breed. Notice the male fish fluttering his fins at the entrance to the cave. The female fish will eventually swim inside the cave and lay the eggs, usually inside the roof. The female will then leave the cave immediately. Female peacock gudgeons lay 50-200 eggs per spawning. Watch the male brood and protect the eggs for 6-7 days. It's important to keep a close eye on the male and the eggs, as you will need to act fast when the eggs start to hatch. The male will stay in the cave with the eggs until they hatch, usually fanning his fins to keep the water circulating. Check the tank a few times each day to make sure that the male is still in the cave. Transfer the PVC pipe to the fry tank as soon as the male leaves. After 6-7 days, the eggs start hatching so the male stops protecting the eggs and will leave the cave. Reach into the tank and cover each end of the pipe with your palms. Lift the cave out of the tank and place it directly onto the substrate in the fry tank. Peacock gudgeon fry are often eaten by the larger fish in the tank. Transferring them into their own tank keeps them safe. As the eggs are hatching, you may notice tiny, ⁄ 8 in (3.2 mm) transparent fry in the cave. Feed the fry 1 tsp (3-4 g) of microworms after 2-4 days. Either purchase microworms from a pet supply store or culture your own. Wait until all of the eggs have hatched and the fry begin swimming. Then drop the microworms directly into the water. After 2-4 days, the fry are big enough to eat food larger than infusoria. Give the fry 10-15 newly hatched brine shrimp twice per day from 1 week old. As the fry get bigger, they can move onto larger live foods. Drop the brine shrimp directly into the tank and watch as the fry race to eat their new food. This amount should be enough for all of the fry that have survived. Peacock gudgeons prefer live food, rather than pellets or flakes. Finding the right amount of food for the fry can be difficult. Try to provide only enough food that's eaten within 5 minutes, so experiment with different amounts until you find what works for your fish. It's safer to give them too little food rather than too much. Clean the tank once per week and change 25% of the water. Place the fish into a small bucket or container filled with tank water. Scrub the sides of the container, vacuum the substrate, and use a measuring jug to replace 25% of the water with fresh, dechlorinated water. Make sure that the water is the correct temperature before you return the fish. It's important to do regular water changes to keep the fry healthy. Schedule cleaning and water changes in your calendar if that helps you remember. Transfer the fish back into your regular aquarium after 2-4 months. Once the peacock gudgeon fry grow into juveniles, they are ready to return to the adult tank with your other fish. Simply use a small aquarium net to catch each fish and place them directly into the new tank. Fish tend to be less frightened of black and green nets, rather than white. 
Add 3 in (7.6 cm) of dark substrate to a 5 US gal (19 L) covered tank. Plant 3-4 live Java ferns in the substrate. Place an airstone in the fry tank. Fill up the tank with dechlorinated tap water. Install a heater to keep the water temperature between 76–80 °F (24–27 °C). Check that the pH is 6.5-7.5 and the water hardness is 5-10 dGH. Treat the water if necessary using water quality adjustment products. Get a breeding pair of peacock gudgeons. Place a PVC pipe "cave" into the adult tank. Observe the tank to see the peacock gudgeons breed. Watch the male brood and protect the eggs for 6-7 days. Transfer the PVC pipe to the fry tank as soon as the male leaves. Feed the fry 1 tsp (3-4 g) of microworms after 2-4 days. Give the fry 10-15 newly hatched brine shrimp twice per day from 1 week old. Clean the tank once per week and change 25% of the water. Transfer the fish back into your regular aquarium after 2-4 months. 