ph and plants.

[Dr. Awkward]

Sounds like you are getting a lot of good info. Just wanted to add that the low pH will also kill off your biological filter. A pH lower than 5.5 will kill the bacteria so you're right on the edge. Like you said earlier, crushed coral in the filter will help a lot. I have a tank where the pH runs low, around 5, because I run CO2 and use Aquasoil. I keep the pH right at 7 with crushed coral in the filter. No need to add anything at water changes so it's easy to maintain a steady level.

And X2 on www.aquariumfertilizer.com. You can get what you need and enough to last you years for less than $30.

 

[THE V]

Just wanted to add that the low pH will also kill off your biological filter. A pH lower than 5.5 will kill the bacteria so you're right on the edge.

This is a myth being tossed around. I did a quick search and the only places stating this were aquarium or pond sites. The nitrogen metabolizing bacteria can withstand a very wide range of pH. They are however much more inefficient at the process of metabolizing nitrogen if the pH is outside of the 6-7.5 range. This is called the optimal pH.

http://books.google.com/books?id=ky...t&resnum=2#v=onepage&q=nitrobacter pH&f=false

There are some stains of the genus that are more adapted to a wide range of pH. The exact same genus that lives in our aquariums are also found in soil. So they survive through many things that aquariums sites claim they can't including; drying out, starvation (months to years), freezing, temperatures up to 120F, and high and low pH.

http://www.springerlink.com/content/v241783413445601/
http://books.google.com/books?id=9c...t&resnum=5#v=onepage&q=nitrobacter pH&f=false

Personally I think that these get started by a misunderstanding of the term "optimal" in microbiology/chemistry. In chemistry optimal means that point at which the chemical reaction is the quickest. In microbiology optimal is the point at which the species reproduces the quickest. People often then make the logical fallacy that if this point is the optimal temperature than outside of this point the bacteria die. This is a false assumption that gets people in trouble all the time.

 

[Dr. Awkward]

I don't think it's a myth. I didn't even know about it until my biological filter crashed when I started injecting CO2. I couldn't figure it out because everything had been fine and then bam, ammonia through the roof, but only after the pH dipped down around 5. I tried re-seeding the tank several times but no luck. Once I got the pH back up and re-seeded within 24 hours the ammonia went back down to 0ppm and stayed there.

A few weeks later I just happened to be reading a copy of Tropical Fish Hobbyist Magazine and they were talking about the dangers of keeping fish that require low a pH like chocolate gouramis because you can overdo it and kill your bacteria. That's where I got the 5.5 pH figure. I trust those guys.

I'm sure some of the bacteria survive at a low pH but in my case it wasn't enough to keep the biological filter going.

 

[THE V]

^ What you just stated is an excellent example of my point. The bacteria were very likely not dead they had just become very inefficient at metabolizing the ammonia and nitrite. This means that they grew very slowly and the waste built up in the tank. Remember just because bacteria are not currently eating much doesn't mean they are dead. Nitrifying bacteria live in very harsh conditions and can take a lot before they die. Nitrosomas physiologically doesn't make any changes for up to a month of starvation.

BTW the pH of when this build up occurs is dependent upon the species and strain of bacteria in your tank.

 

[Deneault]

Thanks for all the informantion, its great.

 

[Dr. Awkward]

Okay, I don't know if the bacteria were dead or alive. I just know they weren't breaking down ammonia. I should have written that the low pH will make your biological filter stop working, which in my book is just as bad as dead because it will lead to dead fish.

I wouldn't call it a myth because you'll make people think their biological filter will work if their pH suddenly drops below 5.5, which it won't. It's hard enough explaining to new fish keepers how a biological filter works. This doesn't apply to you Deneault, you obviously know what your doing here.

 

[Deneault]

Pet stores don't usually carry Nitrate based fertilizer. You can go to your local hardware/garden store and look for Calcium or Potassium Nitrate or you can just order them online.

Here's a decent one.

http://www.aquariumfertilizer.com/index.asp?Option1=cats&Edit=2&EditU=1&Regit=2

if i buy these from my local hardware/gareden shop, what will be the dosing i need?

Btw ph is on the raise slowly, nearly at 6.5

 

[KarlTh]

Okay, I don't know if the bacteria were dead or alive. I just know they weren't breaking down ammonia. I should have written that the low pH will make your biological filter stop working, which in my book is just as bad as dead because it will lead to dead fish.

I wouldn't call it a myth because you'll make people think their biological filter will work if their pH suddenly drops below 5.5, which it won't. It's hard enough explaining to new fish keepers how a biological filter works. This doesn't apply to you Deneault, you obviously know what your doing here.

The difference is that if they're dead, then the tank must cycle again. If they're just inhibited, then they'll perk up again as soon as the pH is raised.

 

[Dr. Awkward]

Here is a link to the EI dosing schedule. I've been using those tiny measuring spoons with cutesy names like "dash" and "pinch." The set I have starts with 1/8tsp and goes down to 1/64tsp.

The bacteria didn't perk up fast. The ammonia didn't budge until I re-seeded with bacteria from a different tank. The tank had been running for at least a week with a pH of 7 and nothing happened. That's when I re-seeded - which immediately got the cycle going again. I'm just glad I didn't have fish in there yet or they would all be dead. I don't know how long it takes for the bacteria to recover from the low pH but it was too long for me.