Doing A Fishless Cycle But Ammonia Levels Aren't Dropping..?

[Miss Wiggle]

i think he may have meant the pH is it 6 could be wrong though!

 

[waterdrop]

Yeah Colin, she reads my mind perfectly. My pH was down to 6.0 again, not my ammonia level. Brings up another newbie question from me though: what is the main driving force behind pH dropping during fishless cycling? What's the chemistry that's going on?

 

[Colin_T]

Beats me I haven't tested the PH of a cycling tank since the 70s
My tanks never fluctuated anyway but I guess it would be to do with the ammonia going in. Ammonia & nitrite are slightly acidic and even at low doses could drop the PH of the water if there isn't enough carbonate hardness to keep the PH stabile.

 

[waterdrop]

Yes, one would think it has to be the ammonia and/or nitrite as those are the significant water chem things going on.. I wonder if a bacterial bloom could play a role? Both times my pH has dropped to 6.0 there have been visible bacterial blooms. And another interesting thing, now that I'm thinking about it: I bought a KH test kit, a TetraTest one I believe (KH is Carbonate Hardness, right?) and when I first used it I had this happen: You are supposed to drip blue reagent drops into the water sample. The number of drops it takes to turn it yellow is the hardness number. My sample turned yellow on the very first drop. This would indicate very soft water, right? But I could swear we have very typical american suburban hard water. I just decided the reagent must be expired or bad. I've had a thought now and then to take a sample to the water authority to verify, and I've run the test again with the same result. I haven't persued it because KH didn't seem to serve any particular need for me yet. But maybe my carbonate hardness really is low for some reason and that is why its easy for my pH to drop to 6 and my fishless cycle to stall - its a thought! (I realize I'm referring to hardness and softness here as if we were talking about general hardness rather than carbonate hardness, so correct me if this is bad practice.)

 

[Colin_T]

Bacterial blooms can drop the PH of water too. Beneficial filter bacteria consume oxygen and the more bacteria in the tank, the more oxygen they require. They breathe in oxygen but breathe out carbon dioxide (CO2) which is acidic. SO if you have a lot of bacteria in the tank they could be producing so much CO2 the PH drops.

KH is carbonate hardness. They use a K because of the German spelling for "karbonate". Carbonate hardness refers to the dissolved carbonates and bicarbonates in the water.
General hardness is all the dissolved minerals in water and usually consists of calcium, magnesium and sodium but can include other minerals or just one or two minerals. The more minerals dissolved in the water, the harder the water.
You can have hard or soft water anywhere in the country. If you get mainly rain water or Desalinated water then it will probably be soft and have very little mineral content in it. If you get bore or underground water it could be hard or soft.

If your KH test kit is changing colour after 1 drop is added, your water has little to no carbonates in them. Carbonates are used to buffer the acids in the water and keep the PH stabile. Try adding a tiny amount of sodium bicarb (baking soda) to the test phial and swirl it around. Then test the KH of the sample. It should be really high. You can use sodium bicarb to buffer or raise the PH of the tank water.

 

[waterdrop]

thx I'm going to do the little baking soda test to see if my KH reagent is good

 

[Miss Wiggle]

way i see it is when the tank is cycling it's obviously new, all the plants, bogwood, gravel etc etc etc are new, this means there's thousands of chemical reactions going on while everything settles in. this means all sorts of levels go loopy and one of the main things we test for is pH and it's all over the place when cycling a lot of the time. I reckon if we were alo testing every other chemical that's in the water a fair few of them would be all over the place too.

 

[Colin_T]

very porobably wigglie

 

[waterdrop]

No, its friday night and she's either loopy or wiggly

OK.. I put a couple drops of my supposedly dead TetraTest KH reagent into 5ml of my tank water and it looked extremely pale yellow as every time before. I then took a tiny pinch of baking powder (Rumford Premium Aluminum-free double-acting gluten-free from the little red can ok I'll shut up) and WOW, Colin is right once again (as ever?) and I got pale blue right away... Sooo, maybe the test is right and my carbonate hardness is ZERO!

Let's assume this is right for now. What does this mean? Is this a significant contributor to my rapid drops from pH of 7.4 tap water down to pH 6.0 (well by rapid I mean a period of days, not sure how many)? Only reason I care at all is that when it hits 6 I do a 75% water change and recharge the ammonia back up to 5-6ppm so that hopefully my fishless cycling won't stall.

~~waterdrop~~

 

[Colin_T]

I then took a tiny pinch of baking powder (Rumford Premium Aluminum-free double-acting gluten-free from the little red can ok I'll shut up)

LOL, the salesman saw you coming. What sort of bicarb is that Premium aluminium free, double acting gluten. . . .

Is this a significant contributor to my rapid drops from pH of 7.4 tap water down to pH 6.0 (well by rapid I mean a period of days, not sure how many)?
~~waterdrop~~

Yep, absolutely. If there are no carbonates (or bicarbonates) then there is nothing in the water to stop the PH dropping. The PH can literally plummet overnight. It can be 7.5 before bed and when you get up in the morning it can be 5.5.
Get a piece of limestone rock or some shells and put them in the tank. They are made from calcium carbonate and will help to buffer the acids in the water and limit or prevent the PH dropping.
You might need a few bits of limestone but add a couple and see how the PH goes. Over a course of several weeks you can add or remove it and see what effect it has on the pH.

 

[waterdrop]

I then took a tiny pinch of baking powder (Rumford Premium Aluminum-free double-acting gluten-free from the little red can ok I'll shut up)

LOL, the salesman saw you coming. What sort of bicarb is that Premium aluminium free, double acting gluten. . . .
<...>

LOL, well, "Ingredients: Monocalcium Phosphate, Bicarbonate of Soda, Cornstarch (from Nongenetically Modified Corn)." and the product page says "an All-Phosphate baking powder."

Immerse yourself : [URL="http/www.rumfordworld.com/htdocs/rumford.htm"]http/www.rumfordworld.com/htdocs/rumford.htm[/URL]
[URL="http/en.wikipedia.org/wiki/Count_Rumford"]http/en.wikipedia.org/wiki/Count_Rumford[/URL]
[URL="http/en.wikipedia.org/wiki/Baking_powder"]http/en.wikipedia.org/wiki/Baking_powder[/URL]

I'll get back to the practical fishkeeping part later (I still can't make myself believe that our town water has no carbonates. I might just have to make that trip to the water authority laboratories after all. Besides, doesn't every aquarist want to get to know his water authority lab guy and get to see his test bench? )

~~waterdrop~~

 

[Colin_T]

Wow they actually add stuff to baking powder over there. Ok no need to use that type of baking powder
If you need to raise the PH of the water just use sodium bicarbonate with nothing else added to it.

 

[waterdrop]

but I couda been raising my morning biscuits in that high temp fishless cycling oven.. aah

 

[Colin_T]

LOL
add some driftwood to the tank and you have tea to go with the bickies