DIY internal filter using submersible pump and two liter soda bottle

Aquarium filters are critical for maintaining aquarium water quality. Without an adequate filter, ammonium can accumulate. Even small amount of ammonium can be lethal to the fish. Filter also remove the excess nutrient which encourage algae grown.  Filter also mechanically remove the food waste and plant debris from the water.  It make the water crystal clear.  There are several reason that I wanted to make the DIY internal filter:

  1. Commercial off the shelf filter can be expensive. The most expensive part is submersible pump which causes about $8 on Amazon. Total cost is about $10 each if I made multiples for the material buy in bulk. There are cheap internal filter from Amazon. Those are just sponge filters, no biological filteration.
  2. It’s custom made so I can pack more biological filtration
  3. It use submersible pump (much quieter than the air pump).
  4. Easy to clean
  5. proof that it works.

Material needed: Submersible pump, 2 liter soda bottle, Rain bird Barbed elbows, sponge (Cut of from 17 in x 24 in, I can make 24 of them) , vinyl tubing (0.5 in ID), larva rock (0.5  cubic feet) from home depot.

Here is how I do it.

  1. Crush the larvae rocks if they are too big, remove heave ones (I think they are just bricks). clean thoroughly.
  2. Cut the soda bottle around the body where the diameter just become to narrow.
  3. Cut the sponge so the diameter is slightly bigger than the soda bottle opening and cut the hole around the center of the sponge.
  4. Cut a piece of 1/2 in vinyl tubing so it is an inch above the rim of the soda bottle opening after connected to the pump.
  5. Connect the Barbed Elbow
  6. Begin filling in the larva rocks
  7. Place the sponge into the opening of the soda bottle.
  8. That’s it. Drop it into the back of the aquarium and connect the power.



Vallisneria Spiralis, Italian Vals

Italian are used in my Angle fish tank to block the sights from aggressive angels to milder angels

Vallisneria Spiralis, AKS Italian Vals, are excellent background plants. They do well in just about all water types and lighting.  Italian vals can grow up to two feet tall.  You can cut the leaves to any height without damaging the plant which make them suitable for shorter tank (less than one foot tall). The Italian vals are mostly green. Under strong light, they my display copper, purple red to purple in color.

Italian vals are used as background plants in my 55 Gallon community tank.

They provide great hide out for my Red Cherry Shrimps

Italian Vals in my guppy/Pleco tank.

Planting Italian vals: Planting Italian val up to the base of the leaves into the substrate, Planting the plant too deep may cause the Vals to melt. They are not picky about the substrate but they grow much better with enriched substrates.  They are mostly root feeder but also absorb some nutrient from water column. The plants are propagate by sending out runners on or just below the surface of the substrate.

DIY root tabs

To support optimum plant growth, aquarists sometimes add fertilizer at initial tank set up.  This will promote strong root system, the absorption of nutrients and overall health of the plant.  Sometimes, root tabs are also added periodically after initial set up to maintain the look of the plants, particularly the strong root feeders, like Amazon swords. There are commercially available root tabs but they are not cheap.  Seachem Flourish Tab costs $20 for 40 tabs.   The cheaper option is using the slow released fertilizer available in garden center. They are encapsulated in granules but they are easily breakable and released the fertilizer into the water column while inserting them into the substrate.  The trick is encapsulate them into gel capsules and insert the gel capsules into the substrate. The gel capsules will be melted after immersed in water thus exposed the slow released fertilizer.

I used Osmocote plus and size 00 gel capsules. The cost is about the same but I can make thousands of them.

Signs of plant nutrient deficiency:

Tips for Caring Your Ramshorn Snails

Ramshorn snails are common fresh water snails.  They have different variantes; pink, red, blue, brown or leopard.   They are active, fun to watch and very useful too.  Ramshorn snails eat all kinds of algae, uneaten food, fish waste and decaying plant matter.  They are the best cleanup crew for your aquarium.   Despite easy to be care for, here are a few tips to keep them (and your aquarium) healthier:

  • Fortify your aquarium water with calcium rich substrate, such as crushed coral or provide calcium supplements in their diet if your water is soft. Shell erosion is a good sign of calcium deficiency.
  • Check the ingredient of your aquarium fertilizer and make that these is no copper. Invertebrates, like snails, have very low tolerance of copper.
  • Ramshorn snails are good community snails.  They don’t harm other tank mates or eat live plants but aggressive fish might eat or harass them.
  • Control breeding: do not overfeed. The more you feed the faster they grow and the faster they reproduce.  Remove uneaten food five minutes after feeding. That will ensure that they will have nothing to eat other than the algae.
  • They have higher bio-load than other types of invertebrates, like shrimps.  Twenty percent weekly water change is recommended.
  • What if they are over populated your aquarium?
    • Bait them and remove them from the aquarium. They make nice treats for puffers, loaches and turtles.
    • Put several assassin snails in the aquarium.

Other articles about Ramshorn snails

Ramhorn Snail babies hatched in 9 days

Ramhorn Snail babies hatched in 9 days

My Ramshorn snails wasted no time on depositing her eggs in the temporary plastic container as I was moving them to the new tank. I followed the development of the embryo for nine days.

Day 1: The female snail deposited 10 eggs with a transparent egg sac.  They were just white dots within the egg.

Day 2: It become somewhat transparent. All cells are undifferentiated.

Day 3: Still rounded shape but the egg become more transparent and more cell within. Rather than staying in one spot now the embryos are spinning and floating around.

Day 4: The shape of the embryos are somewhat irregular but still are generally oval shape.

Day 5: The body started to fold. The foot and shell can be distinguished.

Day 6: It’s more like a snail now.  I can clearly see the shell part and the foot. The shell look like a cap.

Day 7: More development. The some of the shells are in dpiral form. It looks like a Ramshorn now!

Day 8: Getting crowed. There is very little space left in the cell.

Day 9: The individual egg shells are broken. All baby snails are moving around within the egg sac. Later in the day, all snails break free from the globule and moving around in the container.

Continue following up with those 10 baby ramdhorn snail: 26 days after they were hatched (35 days from fertilized eggs). They laid eggs today. There are total 5 egg clusters. The size of the snails are about 3/8 of an inch.


Windowsill Aquarium

Windowsills offer plenty of sunlight for aquatic plant. It’s a great place for a small aquarium if space is limited. It’s self sustainable. The sunlight provides the energy for the algae grow which feed the aquatic animals, such as snails, shrimps and small fish.

Here is my mini-aquarium at my south facing window. The aquarium is a actually an food container purchased from Target.  I placed the organic potting soil first then top-dressed with gravel (about one inch deep each). I press tiger lily bulb into the gravel then dropped two different types of moss: java moss and an unknown land moss collected from park.

Who else lives in the windowsill aquarium?

Red Cherry Shrimp
Ramshorn Snail
A ramshorn snail baby on the land moss. The original foliage of the land moss melted away but the new shoots are growing.
Moina (closely related to the better known water flee, Daphnia)

Tips for keeping the algae in control in a windowsill aquarium:

  1. Keep algae organisms in the aquarium, such as snails, shrimp and Daphnia
  2. Start with plenty of plants to deplete the nutrient for the algae.



Red Cherry Shrimp (Neocaridina davidi) Breeding Journal

Red cherry shrimp is very colorful and easy to breed shrimp.  Everyone knows that the color of the shrimp will develop over the lift time and it takes about 2 to 3 month to produce a new generation. In this post, I am recording the size and color of the shrimp developed over time.

This is where it started with a berried fire red cherry shrimp.

Berried Red Cherry Shrimp Photo
Day -1 (5/17/2019) Berried Red Cherry Shrimp. The eyes of the shrimplet within the egg are clearly visible.
Day 1 (5/18/2019) Red cherry shrimp babies were born. They are not actively at all. Most of them are clinging to the sponge filter. Most of them are pale white


Day 7 (5/25/2019) one week old, Most shrimp develop red color (mostly translucent orange). They are moving around the tank and eating the Crab Cuisine that I feed. The size is about 1/16 inch.
Day 14 (6/2/2019). Two weeks old. Almost double in size to about 2/16 in. Developed more red color.
Day 21 (6/9/2019). Three weeks old. Size is about 4/16 in.
Day 28 (6/16/2019) Four weeks old. the color is amazing. most of the shrimp developed deep red colored dots all over their bodies.  The size is approximately 6/16 in. They eat a lot. I have to feed 3 pallets everyday now.
Day 34 (6/23/2019, approx 5 weeks). They are about 7/16 inch long.
The colony is swarming for the first time. They were swimming like crazy in figure 8 path.
Found some molts in the tank. Expect this will be going on for several days as they were born approximately the same time.

Day 42 (6 weeks, 6/30/2019) most of them are above 1/2 in long. Gradually see some sex differences but still hard to confirm without a saddle.

Day 51 (7/9/2019) seeing the saddle on female for the first sign.

Day 63 not much going on. the saddle are getting longer and more female shrimps now have a saddle.

Day 66 (July 24) A berried female was found

Day 68 (7/26 another berried female was found)  Move both females to tank #2

Day 70 (7/28 3rd berried female was found)

Day 85 (3 more berried females, the first two berried females gave birth). The baby shrimps are raised separately from other shrimps. These will form the line for quicker maturity.  Another line will be richer color.

Day 91 and Day 92 (8/18 – 8/19 There is one shrimp died for consecutive days). It’s time to release more shrimps to the community tanks.  It’s just not possible to keep that many shrimps in a tank with less than one gallon water.

Tank 1 and tank 2 are early matures. Tank 3 consists the original colony selected for color. Tanks 3 now has 17 shrimps, including 9 females and 8 males or unknown (They have no clear female characteristics: saddles or egged, or body plates but they have thicker body and colorful body. They might be slower to mature.).

First time getting the shrimp head count:

2 dead during the the first 92 days.

Total shrimps: 36 for this brood, including 13 females, 13 male + unknown, 2 dead


8//13/2019: 5 males and 1 female (less colorful) were release to the community tank – the breeding tank is a little bit over crowed.

8/19/2019: 8 males and 3 females were release to day. Those are less colorful ones.

DIY Mattenfilter using fountain pump

Mattenfilter is an effective and affordable alternative to more expensive and complicated option, canister filter and hang on the back filter.  Compared to the regular sponge filter, it has larger surface area.  Using an air pump is a popular option for providing the water flow but I don’t like the noise from the air pump.  Power head is much quieter than the air pump.  Most power heads rated 150+ gallon per hour which is much more than what I need it for my 20 gallon tanks. I found some smaller fountain pump might be just enough and cheaper too.  Here is what I did:

  1. Measure the interior height and depth of the aquarium.  For my 20 long tank, it’s 12 in x 11.75 in (W x H) and 10 Gallon tank, it’s 9.75 in x 10 in. The height is measured from bottom to the rim of the tank
  2. Cut the sponge 1/3 inch wider than the depth and the same height as the interior height.
  3. Use a pair of scissor to drill and cut a small opening at one corner of the sponge
  4. Cut a piece of 11 in long vinyl tubing (1/2 in ID and 3/4 OD) and attach it to the fountain pump using the 1/2 in adapter.
  5. Connect the other end of the vinyl tubing to an L-shaped elbow adapter and finish up with another short piece of vinyl tubing as the output of the pump. Tip: Adjust direction of the outlet perpendicular to the curve of the longer piece so that the direction of the output is parallel to the water surface

Cut the sponge to size 1/3 inch wider than the interior depth. I use a scalpel to cut the sponge.

Viewing from the back

Side view of the mattenfilter

The sponge will bulge if the sponge is too wide.

Materials I used:

Tips for cycling the fish tank

Properly cycling your fish tank is critical for starting up your aquarium. Introduce fish prematurely can cause ammonia spike which can be lethal for your fish. Here are some tips for you to properly cycle your fish tank:

  1. Starting your aquarium for matured aquarium: Adding any materials (water, filter and substrate) from and old aquarium can speed up the cycling process.
  2. Having live plant in aquarium
  3. Adding beneficial bacteria from commercial product
  4. Monitoring water quality frequently
  5. Make frequent and small water change
  6. Adding few small and hardy fish first then adding more fish gradually (no more than couple fish at a time weekly)
  7. Feed fish sparingly
  8. Considering adding ammonia neutralizer

Aquascaping is a constantly evolving and learning process

Restarting my old hobby

I was cleaning out my basement. I found out that my 10 gallon and 55 gallon tank were sitting on shelf. The were hided behind a pile of cardboard boxes fully of junkies.  Next to it are buckets of gravels and Rubbermaid tub full of aquarium equipment.  I still remembered how I got into this hobby.  It seems to be forgotten for a long time because of the busy live after moving into my new home.  Now that kids are all grown up and the pace of live seems to be slow down quite a bit. I was thinking about restarting my old hobby.

Setup 10 gallon tank

I wanted to have keep planted shrimp tank.  I started out pool filtered sand as substrate, a main wonderstone rock and a few plants.  Staurogyne Repens on the foreground and  Vallisneria spiralis (Italian Val) as the background. I tied up Java moss on a piece of rock and tree branches.  The branches is from a dead oak tree.  That’s my initial set up.  Couple weeks later, I introduced some ghost shrimps to cycle the tank.

A month later, I introduced the Red Cherry Shrimp and Otocinclaus Catfish.  I replace the Wonderstone rock with milk quartz. The pH seems to drop a little. I also added Alternanthera Reineckii Mini to add color, Marimo mass over rocks and water wisteria to the left corner.  Hopefully, it will cover the equipment after it’s fully grown.

The plants were growing well at all with sand substrate.  Another month later, I re-scaping the tank over with organic potting soil with sand over the top. Adding a few other plants: Red flame sword (Echinodorus), Alternanthera Reineckii Cardinalis, four-leaf clover (Marsilea quadrifolia) and Monte Carlo on the foreground and the top of the milk quartz.  

One month later, I removed the “moss tree” as it was too close to the light.  It was full of hair algae. The potting soil substrate really works. My plants are growing well.

Now, it seems to be a little bit over grown and requires a little pruning.

My red cherry shrimps are shriving. They have been producing babies.