Phosphate and PH

[Joe80]

Hello everyone. I’d like to remove phosphate from my aquarium because of algae growth. My tap water has 1.3 phosphates. So I want to use a Phos-pad in my filter to reduce algae growth.
My question is, will removing Phosphate alter my PH?
Cheers

 

[Guyb93]

I’m guessing yes @Essjay knows water chemistry

 

[Essjay]

Hmmm, I don't think so


You could try leaving a pad in a bucket of water to see what happens to the pH, and leave another container of water with nothing added to stand alongside it - if the pH in the water with pad does change, you need to know whether it would have changed anyway by just leaving water to stand.

 

[Colin_T]

Removing phosphate shouldn't make any difference to the pH.

If you have an algae problem, either add more live plants to use the nutrients, reduce the lighting, or do a few more water changes to help dilute nutrients.

 

[Joe80]

Hmmm, I don't think so


You could try leaving a pad in a bucket of water to see what happens to the pH, and leave another container of water with nothing added to stand alongside it - if the pH in the water with pad does change, you need to know whether it would have changed anyway by just leaving water to stand.

Good idea I’ll do a test ??I heard that phosphates help with buffering of water. So I thought it might alter the water if it was removed.

 

[Joe80]

Removing phosphate shouldn't make any difference to the pH.

If you have an algae problem, either add more live plants to use the nutrients, reduce the lighting, or do a few more water changes to help dilute nutrients.

I currently do 40 - 50% a week. My tap water in pretty high in phosphates anyway so not sure that increasing the water changes would help much.

 

[Colin_T]

You could get a reverse osmosis (R/O) unit to clean the tap water up and remove things from it, or set up a holding tank/ container with tap water and put a heap of floating plants in it. Leave the plants in there until the nitrate and phosphate is at 0ppm, then use that water to do water changes on the main tank.

 

[Joe80]

So I did the test. I filled two buckets with 10 litres of water in each. One bucket I put a small piece of Phos-pad ( super fish brand ) in the water, 4” x 3” in size. I let the buckets sit for about 60 hours. This morning I gave the buckets a stir and did a load of tests.
Phosphate levels in the bucket with the phos- pad in had drop a tiny amount... not much at all but the API test showed a slightly lighter shade of blue / green, so the phos-pad removed a very small amount of phosphate. I guess that if the pad was in a proper filter it would be more effective.
PH / KH / GH remained the same in both buckets. So on this very small scale ( not particularly scientific test ), the phos-pad did not change the water parameters.

 

[Joe80]

You could get a reverse osmosis (R/O) unit to clean the tap water up and remove things from it, or set up a holding tank/ container with tap water and put a heap of floating plants in it. Leave the plants in there until the nitrate and phosphate is at 0ppm, then use that water to do water changes on the main tank.

Thanks Colin. Yeah I have been toying with idea of going RO for a while now. Main goal would be to reduce tap water phosphates, nitrates. Thing that holding me back is the worry about the possible ph swings. I am happy with my ph but it could be nearer neutral. Everything I read says that stable ph is the most important thing. So not sure if it’s worth the risk.

Good idea about the plants, sadly I live in a small apartment so that’s not very practical.

I currently use a pozzani nitrate filter... which work very well. It’s just phosphates that are a pain

 

[Colin_T]

They have a substance that removes phosphates from marine tanks. It's like carbon. Maybe you can try filtering the water through that before using it in the tank.