[ponyo]

So a few weeks ago I asked about cycling my new 17gal riparium and explained I wouldn't be around to do testing/adding ammonia etc. Here's what ended up happening:

I set the tank up about 2 weeks ago IIRC. I used a small in-tank filter that I modified a little bit: I cut a piece of sponge from my 29gal established tank HOB filter and put that in place of the clean sponge that came with the small filter. I removed the carbon layer and instead I put some of the ceramic-bead things that came from my HOB filter. I don't know if that was a good idea or not.... I added all RO water to the tank and added the equilibrium. It sat like that for a week with a pH of about 6.4 When I got back the next weekend I added more equilibrium to bring it up to a pH of 6.8

Then I had my mom feed the tank with fish food once a day as if there was a fish in the tank. She has done this for a week. There is now a lot of brown "dirt" on the bottom of the tank that I am hoping is not algae--the food I used was new life spectrum small fish food--little tiny pellets. I tested the water this morning: ammonia: 0 nitrites: 0 and nitrates: 10 ppm

Should I presume it is cycled? My 29gal planted tank maintains 5 ppm nitrates so 10 seems a little high from what I'm used to but I don't use RO water in my 29 gal (yet). I don't know if that makes a difference.

I just have one betta fish I plan to put in this tank. Will one fish not be enough to keep it cycled? I might add some algae eaters in the future, not sure but right now I just have one fish for it.

 

[Diana]

Took media from a cycled tank = good.
Let it sit for a week at pH under 7 and with no food = bad.
Started feeding it with fish food = good.

Is the pH still really low?
Equilibrium does not alter the pH. It adds certain minerals that do not usually act as buffers for pH.

Add carbonates to raise the pH. Potassium bicarbonate or sodium bicarbonate (baking soda) are both good sources of carbonates. Raising the KH will pretty much always raise the pH when you are starting with RO water. It also gives the nitrifying bacteria the carbon source they use.

NLS for small fish probably does decompose pretty fast (it starts off small, so plenty of surface area for microorganisms to get started).

Brown stuff on floor of tank might be remnants of NLS or it could be diatoms.

One fish will keep a tank cycled with enough bacteria to handle the waste from one fish.

It does not matter how many or how few fish are in there. The bacteria will grow or shrink to match the bio load. When you add more fish you should add more bacteria. Otherwise the tank will cycle again as the bacteria grow to match the new load. All the fish may be exposed to ammonia and nitrite while this happens.

Ammonia and nitrite at 0 and rising nitrates suggests the tank is cycled.
Monitor the situation, and perhaps add a bit more fish food than you will be feeding the Betta for a few days. Fish food is the main source of nitrogen, and therefore ammonia, so if the bacteria can handle it when you add more, it should be just fine when you actually have a fish in there and feed less fish food.

 

[ponyo]

Thanks for your answers!!!

The pH dropped back to 6.4. I added a little more equilibrium and the pH went to 6.6 but I doubt it will maintain that Should I adjust the pH? Do people using RO water usually adjust it? I put in more than I think I should of the equilibrium and the GH is 4. KH is 1.

I have the Seachem acid and base buffers for raising/lowering pH (they are in a solid forum) and I also have the Seachem neutralizing buffer that allegedly brings the pH to 7. Should I use the base buffer or try the neutralizing buffer? Chemistry was not my strong suit.

 

[Diana]

KH is a buffer for pH.
KH of only 1 degree is so soft the pH can be almost anything at all; other things in the water like organic acids or CO2 will control the pH.

I would raise the KH to about 3 degrees and see what that does to the pH. Add carbonates. Potassium bicarbonate, or sodium bicarbonate (baking soda) are the most common materials.

I would read the labels on the products you have. If any contain carbonates use that. Use it in small doses and make sure you allow it to dissolve before you test the result. You could dissolve it in a small jar of water and pour it into the tank, then test after it has circulated.

Yes, people who use pure RO usually adjust it. They might blend it with tap water and the tap water supplies the minerals.They might add minerals in the form of GH booster and a source of carbonates.
Pure RO does not have the minerals that plants and animals need.
The ways they adjust it depend on the livestock.

Soft water fish: Add a GH booster and a source of carbonates so the GH and KH are between 3-5 degrees. (research the exact value if you will be keeping or breeding something wild or delicate)

Hard water fish: Add GH booster and a source of carbonates so the GH and KH are between 10-20 degrees. (Again, research the fish you want to keep to determine optimum levels).

Nitrifying bacteria need the carbon from carbonates. If the KH is too low they do not grow well. They need a little bit of other minerals, too. While I am cycling a tank I keep the GH and KH about 10 degrees, and add some plant fertilizer (KH2PO4) and micros. The pH in a tank I am cycling will be well into the upper 7s.
The scientists who study these organisms keep them in even harder, more alkaline water.
This is OK while you are cycling the tank, then a big water change when you are ready to add fish can be adjusted so the water is suitable for soft water fish, if that is what you are going to keep in the tank. While you are growing the bacteria (cycling the tank) you want them to grow fast. Provide optimum conditions to grow. After the population is big you can alter the water because it is OK if they are not growing and reproducing so fast. Just enough to keep up with the fish population. And plants are helping with biofiltration.

Chemistry was not my strong suit

You will never learn any younger!

 

[jrman83]

You can also bring up kh by adding a filter bag with crushed coral in it. You will need to slowly add to get your desired effect. Just easier than adding baking soda after every water change.