One Barrel System Questions and Answers

One Barrel AP System

Phil emailed after our last class with these questions. Thanks Phil!

Q: “I have checked the pluming and it is leaking from the drain and the inlet”

A small leak won’t matter

If the hole you drilled is a close fit and the surface is smooth on both sides, the small drips may stop as the system ages.

If you drill a 1” hole for the ¾” drain (gray PVP electrical terminal) fitting and a 13/16” hole for the ½” inlet (gray PVC electrical terminal) fitting, the holes will be tight enough to resisting leaking, without using a washer.

Teflon tape keeps threads from leaking and that’s usually not where it leaks. Leaks are often because of holes too large or surfaces not smooth and flat around the hole. The washer I mentioned in class is hard to find and did not work well.

If you want to try a washer you might make one. A sheet of rubber like that for making the pan in a tiled shower could be cut with a sharp screwdriver and hammer but be careful!

Likely easiest fix is to use some silicon filler but you will need to let your system drain and dry. Do this to the fitting that is leaking.

Apply silicon on the male piece where it seats and fill around the threads just where they touch the hole in the barrel, then tighten the female piece and let it dry over night. Add water and test for a while.


Q: “I have heard that a bucket of lake water will shorten the cycling time by allowing the fish to be placed in the tank immediately.”

If you put lake water into your system likely it will have the good bacteria you are looking for, but they won’t be established in your system, just in your water. I.E. there will only be a few. That will make them available to start, but doesn’t assure they will be there when needed as the Nitrogen cycle grows the large amount of bacteria that a system needs.

The Nitrogen cycle is mostly a sequential process

You will need “pure” Ammonia present to start the Nitrogen cycle. Then the Nitrosomonas bacteria need to find it, eat it, and produce Nitrites as waste. Next the Nitrobacteria or Nitrospira bacteria will need to find it and produce Nitrate as waste. Then the plants will need to eat the Nitrate cleaning the water for the fish.

Ways to start a new system

1/ Put some water and media from an operating system into the new system. Water has to be moved quickly to avoid bacteria dying from heat and lack of air. Add 10 small Goldfish and several small plants into the system. You could offer to clean out the sludge from an operational system in return for taking it to use in your new system.

2/ Put 10 small Goldfish and several small plants into the system. Add a cup or two of worm tea, or ½ cup of worm castings. This will introduce the good bacteria into the system and accelerate startup.

3/ Put 10 small Goldfish and several small plants into the system. System will start slower but will work fine.

4/ Put several small plants into the system.

The cycle doesn’t start the instant the tank is set up. An ongoing supply of ammonia must be present for the process to begin. Add enough “pure” Ammonia to get the Ammonia reading up to 5 parts per million. Remember how much Ammonia that took. For example perhaps 2 teaspoons. Then add that amount daily and measure the system cycling. This mimics the fish being in the system adding their Ammonia daily. If you miss a day, your system biology may die, basically starting over. It is easier to just use cheap fish.

5/ Put 10 small Goldfish and several small plants into the system. Add a gallon or two of lake water. This will introduce the good bacteria into the system and accelerate startup. It will also introduce lots of other creatures and bacteria. Sometimes all goes well. Sometimes you get system activity you don’t want. I’d avoid this method while learning.

Feed the fish the maximum they will consume in 30 minutes and remove the rest.

Whichever way you startup your system, you will want to monitor the Ammonia, Nitrites and Nitrates. The Ammonia will start high and there will be no Nitrites and Nitrates.

Then there will be high Ammonia and Nitrites and no or little Nitrates.

Next there will be high Ammonia, Nitrites, and Nitrates.

As all biology is established, there will be Low to no Ammonia, low Nitrites, and medium to high Nitrates.

I would recommend # 3 or #2 for starting your system. Less variables and better environment in which to learn.

Startup Tool

I have constructed a spreadsheet to help you see and track what happens during sthe Nitrogen Startup Cycle.

Look here on
or here on


Your system pH is good to measure as well as it is an indicator of system health. A pH of 7.0 is a good target. Make sure the water you add to your system is de-chlorinated or filtered rainwater. If the pH is above 7, adjust it down with pH down solutions like a mild Phosphoric acid, and add and adjust very slowly.


“I plan to build a greenhouse to try to avoid the hot Texas weather and have it run all year around.”

Greenhouses are great for several reasons. Growing in the summer heat is the least valuable reason. They tend to collect too much heat and ventilating that extra heat is challenging. Make sure you have a ventilation system that is very efficient and automated. Fans can supplement this but there is no better way to vent than having a natural venting process. A ridge row vent and vents near the bottom long walls causes a chimney effect that works well.

Greenhouses are often known as “hot houses”. This is because they collect heat. This is helpful in winter for prolonging the growing season. Also they protect plants from weather damage and many pests. Remember many plants need to be pollinated and greenhouses discourage bees and insects from doing that for you. A wall that opens up to admit pollinators in the spring is a good idea.

 Join our NewsletterName: Email: We respect your email privacyYour email addresss is protected by AWeber

Click Here to Leave a Comment Below