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Raising the PH of a new tank to start filter bacteria.

JohnC

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14 Nov 2008
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On a mountain in the Highlands of Scotland
Hey,

I'm so used to planted tanks and our lovely soils that it's been a while since I'd done a new plant less one. Added to this there is a complexity of tap water with tiny amounts of natural hardness and a ph of around 6.2....

Since the "friendly" bacteria in the various shop bought filter colony products prefer the ph above 7.2 to get established quickly I'm pondering on ways to buffer and raise the ph of the initial tank water.

which then over the following weeks water changes (i'm not going to be in charge of them) will naturally dilute down to the range of the tap water (with a little GH/KH booster added in each water change).

thinking of a bi-carb of soda dose on set up with some gh/kh booster.

suggestions of alternative? remembering that it's a short term aim.

Cheers,
John
 
You only really need to get to ~ pH 6.5 for minimal effect (of pH) on the bacteria you're interested in ... my tanks run ~ pH 6.0 - 6.4 (seasonal variation in water reservoir) without issue - except if I bring a water sample into the lfs & they suggest raising the pH ...
You can add baking soda, just use a minimal dose as it obviously raises sodium (if you shop around you may find some potassium bicarb) - lfs suggest to begin at 1teaspoon/10 gal if I'm recalling correctly.
Also check the actual salts used in the GH/KH booster as some brands include Na/K carbonates anyway.

(be careful with adding the powders direct to the aquarium, I had an oto graze on a leaf where some had collected, silly thing vacuumed up a rather large "flake" & was not feeling well for a couple of days - he looked very unwell shortly after & I was surprised he made it through the night)
 
Trying to work out what you're doing, You need to setup the tank with the water you're planning on using. As soon as you start lowering the pH then that bacteria colony you grew at 7.2 will stop working and different bacteria will start to grow. Many black water tanks have low pH and still function, my low tech tanks sit around at pH 6.4. If you already have tanks setup in the same water then take some filter media out of that and stick it in the new filter.

If you want to keep a stable tank then throw a spoonful of oyster shells (chicken grit) into the filter and forget about it.
 
Most bacteria will adjust to pH rather than "stop working" - there may be some lag phases in growth but it's very difficult to annihilate bacteria with such minor changes in pH as the OP is contemplating, further as the changes will be gradual through tank water changes rather than sudden addition of concentrated acid solutions, it's unlikely there will be any effect.
 
The issue is a cycling tank will generate spikes of nitrite and nitrate. If your water is pretty soft and acidic to start with, these spikes can cause the pH to crash and stall the development of nitrospira bacteria (the ones that eat nitrite and turn it into nitrate)

Optimum pH range for the growth of the 2 types of bacteria we are interested in is between 7 and 8. Also, a warmer tank is better for cycling - 30 degrees C is optimal. At the end of a cycle, you always perform a near 100% water change anyway (to clear the nitrate build up), so your water chemistry will go back to the same as your tapwater then. This final water change does not harm the newly formed bacteria at all.

When I cycle tanks without a soil substrate, I add sodium bicarb and use household ammonia to build the filter. With dirt tanks, the soil tends to buffer the water and leach enough ammonia to cycle the filter. The benefit of the soil cycled tank is that the substrate will keep leaching ammonia for a couple of months or so, so you don't have to worry about adding an ammonia source in the time between cycling and adding fish.
 
As soon as you start lowering the pH then that bacteria colony you grew at 7.2 will stop working and different bacteria will start to grow.

This is just not true and in no way supported by the evidence of hundreds of successful fishless cycles. I can point you to dozens of cases of people raising their pH to 8 to cycle then dropping down to 6.5 with a 100% water change after the cycle completes. The tank cycled at pH 8 will still eliminate 4ppm of ammonia within 12 hours after the massive water change at the lower pH.
 
The purpose of raising the pH and adding buffering capacity to the water is to safe-guard against bio-acidification caused by nitrate spikes during the cycle that can crash the pH of soft acidic water below the threshold where nitrospira sp. and nitrosoma sp. bacteria will multiply and be active.
 
Hi all,
If your water is pretty soft and acidic to start with, these spikes can cause the pH to crash and stall the development of nitrospira bacteria (the ones that eat nitrite and turn it into nitrate)
Optimum pH range for the growth of the 2 types of bacteria we are interested in is between 7 and 8. Also, a warmer tank is better for cycling - 30 degrees C is optimal. At the end of a cycle, you always perform a near 100% water change anyway (to clear the nitrate build up), so your water chemistry will go back to the same as your tapwater then. This final water change does not harm the newly formed bacteria at all.
When I cycle tanks without a soil substrate, I add sodium bicarb and use household ammonia to build the filter. With dirt tanks, the soil tends to buffer the water and leach enough ammonia to cycle the filter. The benefit of the soil cycled tank is that the substrate will keep leaching ammonia for a couple of months or so, so you don't have to worry about adding an ammonia source in the time between cycling and adding fish
This is just not true and in no way supported by the evidence of hundreds of successful fishless cycles. I can point you to dozens of cases of people raising their pH to 8 to cycle then dropping down to 6.5 with a 100% water change after the cycle completes. The tank cycled at pH 8 will still eliminate 4ppm of ammonia within 12 hours after the massive water change at the lower pH.
Have a look at <"Cycling a planted tank">, <"Advise for a blackwater tank"> & <"Talking with Diana Walstad">.
Okay I give up at that point.
You mustn't give up.

I've begun to realise that "cycling" is a huge multi-headed hydra, and that you have to keep chopping the heads off. If you don't you'll wake up one morning and, rather than having a cup of coffee, you'll pour some household cleaner into your fish tank.

If you want to keep a stable tank then throw a spoonful of oyster shells (chicken grit) into the filter and forget about it.
I think that is a good idea, unless you want to keep "Black water" fish.

cheers Darrel
 
The purpose of raising the pH and adding buffering capacity to the water is to safe-guard against bio-acidification caused by nitrite spikes during the cycle that can crash the pH of soft acidic water below the threshold where nitrospira sp. and nitrosoma sp. bacteria will multiply and be active.
but what do you think of the paper linked by Mr Teapot?
 
Generally (and I do mean generally), hobbyists cycling their tanks want to build an effective bio filter as quickly as possible so that they can get on with stocking their tank. Fishless cycling with an added ammonia source has been proven time and again as a reliable method of doing this. Properly fishless cycled tanks can be stocked to about 80% capacity as soon as the tank has passed a qualifying week of zero ammonia & zero nitrite. Even the topic linked by Darrel suggests using household ammonia (http://www.ukaps.org/forum/threads/talking-with-diana-walstad.36661/) as long as it is free from surfactants and perfumes (Homebase household is fine - I had them send me the coshh and full ingredients documents and have used it on many tanks)

Any tank with a natural source of ammonia (soil) should cycle itself but I would be hesitant to stock heavily straight away like you can with an aggressively cycled tank.

Planted tanks can mitigate some of the need to cycle this aggressively due to the plant mass - but I'd still rather have a mature biofilter than take the risk on my fishes health. It makes me nervous when people say things like aim to keep ammonia below 0.25 ppm - any detectable free ammonia is harmful to fish - if your kit shows anything but zero - you have a problem.

Which brings us full circle - the quickest way to build a mature bio filter that will eliminate free ammonia and nitrite to undetectable levels is fishless cycling with 4ppm ammonia

2p
 
Hi all,
Fishless cycling with an added ammonia source has been proven time and again as a reliable method of doing this.
Cycling a method that works for some people, but there are a huge number of posts to forums with titles like <"cycle stalled"> to suggest that it isn't fool-proof.

It is "horses for courses". If you are going to have a bare tank you don't have any option other than "fishless cycling" or "sacrificial fish", I'm definitely not suggesting "sacrificial fish" but as soon as you add a substrate and plants you are into a situation with a lot more options.
Even the topic linked by Darrel suggests using household ammonia (http://www.ukaps.org/forum/threads/talking-with-diana-walstad.36661/)
In the thread Diana Walstad suggests using fishless cycling for Rift Lake cichlids, where you would have hard water and may need to introduce a lot of fish in one go.
Planted tanks can mitigate some of the need to cycle this aggressively due to the plant mass - but I'd still rather have a mature biofilter than take the risk on my fishes health.
You aren't taking a risk on your fishes health, realistically it is relying on the biofilter that is taking a risk with fish health. If you look at the scientific literature there is a huge amount of evidence that "microbe & plants" systems are much more efficient than "microbe only" systems. The key metric for biological filtration is oxygen. As long as you dissolved oxygen supply always exceeds your "Biological Oxygen Demand" (BOD), you don't have a problem. I wrote this article specifically for plec. keepers about 10 years ago, but it is relevant to all fish keepers <"Aeration and dissolved oxygen.....">, despite its title it deals a lot with biological filtration.

There is a more complete discussion of "microbe only" and "plant/microbe" systems here (warning it is quite a long thread) <"Using deep gravel.......">.
t makes me nervous when people say things like aim to keep ammonia below 0.25 ppm - any detectable free ammonia is harmful to fish - if your kit shows anything but zero - you have a problem.
In some ways this is the real problem, you can't accurately test for low levels of NH3/NH4+, NO2- or NO3-, even with a lab. full of analytical equipment it isn't straightforward.

We need techniques that allow us to maintain water quality without the need for testing. There is more about the philosophy behind this in <"Wood for tanks"> and the <"Duckweed Index">

cheers Darrel
 
If you look at the scientific literature there is a huge amount of evidence that "microbe & plants" systems are much more efficient than "microbe only" systems.

A new setup by an inexperienced aquarist throwing plants and fish together in an uncycled tank is a recipe for disaster regardless of the scientific data saying otherwise.

Cycling a method that works for some people, but there are a huge number of posts to forums with titles like <"cycle stalled"> to suggest that it isn't fool-proof.

Yes, they stall because of two reasons, the Ph crashes(Kh drops) or nitrite spike to unreadable value, the latter could be waited out though. But that's well known. All you need is a large water change and the bacs start working perfectly again.
 
Please if you really insist on doing a cycle in a bare tank then do it without the bottled germ killing floor cleaner. Get some cheap fish food and feed your invisible fish a small amount daily for a month. Another option would be to throw in some leaf litter or bark that will break down slowly and produce ammonia. While you're at it you might as well not waste money on the crap test kits.

Another option of raising the KH would be cuttlebone. Again I really don't know why you want to do this. John hasn't really explained what his goal for this tank is but if you want to be lazy about the whole thing I would do as I suggest and throw in some cuttlebone or oyster grit into a filter (can use or filter bag) or place it under the substrate or sprinkle it on the bare tank as this will keep the pH at about neutral which you can then forget about.
 
Hi all,
A new setup by an inexperienced aquarist throwing plants and fish together in an uncycled tank is a recipe for disaster regardless of the scientific data saying otherwise.
I don't think any-one is recommending that. I like at least 6 weeks for the plants to grow in, and I always have spare filter sponges etc., but it does depend on the plants to some degree.

For a new tank (and new canister filter) If you offered me the choices of "cycling with ammonia" or "adding 1/3 cover with Amazon Frogbit (Limnobium laevigatum) or Water Lettuce (Pistia stratiotes)" before adding the fish a week later, I'm going to take the plants every time.

This isn't some abstract theory with no practical basis, even if I didn't have a library of scientific references, I'd have the experience of working with "waste water".

I don't what else I can say, other than:

Plants with the aerial advantage (of access to atmospheric CO2) will offer a much faster and more flexible response to changes in bioload than filter bacteria will.

Plant & microbe systems are about an order of magnitude more efficient than microbe alone systems.

Biological filtration is about the oxygen supply exceeding the oxygen demand.

Have a look at this one: <"Application of Eichornia crassipes and Pistia stratiotes for treatment of urban sewage">

cheers Darrel
 
hey again,

thanks for all the reply's so far. great reading as ever.

just to clarify what i'm aiming to do.

set up plantless tank (a few anubias only)
gravel and sand base.
couple of internal filters.

i'm aiming to use this product (http://acrylictankmanufacturing.com/products/water-treatment/biologicals/colony-nitrifying-bacteria/) to kick start the filter bacteria. with heavy aeration and the fish added pretty much the same day as the bacteria.

bacteria need ph 7.2 to 8 (reading the bottle here) and 90ppm min alkalinity. hence the bicarb question.

I'm happy to let the PH and hardness drop off over time.

The tank is not something i'll get too very often so i'll be leaving instructions with the person on when to add fish, how many, when to start feeding etc.

So basically i'm skipping the ammonia source to stimulate the bacteria and just adding them straight, in large quantities. The fish are then added quickly to stop the mass starvation of the same bacteria. With extra oxygen to help things along. As the ph drops with water changes over the coming weeks the now established colony evolves to the right type and size as more fish are added.

John
 
Hi all,
i'm aiming to use this product (http://acrylictankmanufacturing.com/products/water-treatment/biologicals/colony-nitrifying-bacteria/) to kick start the filter bacteria. with heavy aeration and the fish added pretty much the same day as the bacteria.
Don't do it.

I can post you as many floaters as you like for the cost of P&P. Put them in, wait a week, add the fish. Keep changing a reasonable volume of water. If you only have Anubias you don't need to add fertilisers regularly (or any as very small doses), and you are better off with some floaters to diffuse the light.

cheers Darrel
 
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