Someone adding phosphates?

[incognitus]

I had 40 mg/l of nitrate and could not reduce it with ethanol or vinegar. A green montipora digitata bleached because this nitrate level. As my phosphate readings were near 0 added a bit at night with ethanol. My hope was that phosphate was a nutrient limitant. Nitrate drop was obvious.

After 15 days nitrate is below 10 mg/l and montipora is recovering some color and polips are much bigger. Phosphate readings with test remain equal and there is no sign of nuisance algae, but coraline algae on movement pumps is bleaching.

It seems that I was right.

Someone else?

 

[Randy Holmes-Farley]

I think that is a fairly unusual occurrance. More folks see the opposite.

Were you doing anything to export phosphate specifically, such as GFO?

 

[Randy Holmes-Farley]

I think that is a fairly unusual occurrance. More folks see the opposite.

Were you doing anything to export phosphate specifically, such as GFO?

 

[incognitus]

Nor GFO neither algae refugium. It´s just a bacterial nutrient export by the skimmer.

 

[Randy Holmes-Farley]

How are you measuring phosphate?

How much did you add of what?

 

[JordanRivington]

Just what I was looking for...

Just what I was looking for...

I too have 0 nitrates (did a acid rock bath/rodi soak) prior to putting Marco rocks into tank. I dosed with ammonia to ensure plenty of bacteria while my first fish was in QT for 6 weeks. By the end, my nitrates were 80 ppm even with WCs. So I have done 3 50% changes and now the nitrates are down to 40-50ppm. I have been dosing vodka according to the article "..in the trenches..". However, I am thinking with 0 phosphates that I won't be able to reduce nitrates using organic carbon. I also have no luck growing caulerpa in the sump (even with lots of light).

Will adding a little phos. (as long as it is consumed by bacteria along with nitrates) be a good option? Seems like it worked for you incognitus...

So,

1. Will carbon dosing work without phos?
2. Recommendable to add phos. for this (or just stick to large WCs)?
3. What can I add for a source of phos?

Thanks

 

[JordanRivington]

First sentence should be 0 phosphates...

 

[Randy Holmes-Farley]

I really don't think this is generally useful, as the 0 is almost certainly not 0.000 ppm phosphate and there may be plenty to allow for denitrifying bacteria to consume the organics. Not much phosphate is needed for that process.

But if you have tried other methods and just want to try this, a little fish food will add a lot of phosphate. A pH 7 buffer also typically contains phosphate, if you have one around. Even a little cola will have a lot of phosphate.

 

[incognitus]

My tank volume is 140 liters. I add 10 mg of PO4Na3, and 1.5 mililiters of 96º ethanol,is not a lot of phosphate, but worked for me.

I have not tried any different proportions, don´t want to mess. I feel that I can´t get to 0 nitrates this way, but will try more time before increasing anything. Moreover, digitata is happy now so no need to change.

JBL phosphate sensitive

 

[Randy Holmes-Farley]

OK, as long as you like the results!

 

[incognitus]

To continue with nitrate-phosphate behaviour in my tank ...

I reached 5 ppm of nitrate with ethanol+phosphate but this was the end of road. After this level phosphate did not disappeared and 0.1 ppm of phosphate remained. I tried with ethanol only but levels stayed equal.

I switched to vinegar as carbon source and nitrate started again to reduce and have reached 1 ppm level. But phosphate is piling up, and now is 0.2 ppm,this is new for me because this chemical always has vanished in my tank.

Time for GFO now, and a typical aquarium behaviour.