Freshwater: When are phosphates too high?

[Deleted]

Greetings All,

Freshwater fish can tolerate pretty high levels of phosphates, but when are they too high?

It isn't necessary to use a phosphate absorbing medium all the time in a freshwater aquarium -- but if one is used, I suggest API Phos-Zorb or Seachem Phos Guard. These will not leach anything harmful back into the aquarium and do not react with any other products/treatment. 

I read on Seachem's site that some phosphates are actually necessary for the Nitrogen Cycle. 

I have small pouches of Phos Guard in the Aqua Clear filters on my two 20 gallon and my 10 gallon -- but right now, they are just "holding the space" in the 20 extra high and 10 gallon filters (I put a new Phos Guard in after the worm treatment was finished for the 20 gallon high -- that tank for all new media after treatment). I only use one Phos-Zorb in my Rena filter (when I have a pouch in) - one pouch treats 55 gallon -- my tank is 75 gallons. When I do have one pouch in, I just leave it in for 4 to 6 weeks.

Phos Guard and Phos-Zorb only remove so much then is exhausted (2 ppm or so?... I'd have to look it up) .... I started to use phosphate absorbing media to help clear up slightly cloudy water (that wasn't a bacteria bloom -- water straight from the tap was cloudy). At the time, I didn't check phosphate level. I do have a phosphate test kit (purchased in 2011 - but no idea if it is still good). Since I started getting consistent results of 2 ppm or less - never 0, I just stopped testing (the reagents really stained the plastic tube I used....so colors were getting harder to determine. When phosphates are high - around 4 ppm or more - the color is a dark blue. This is the only test that actually stains the plastic tube -- who knew?).

Carl, please post links in the thread (no rush)....Also post any dangers of using liquid products to remove phosphates. I do have one liquid product, but it is too "tricky"....I only used it once (it did work). It does require testing phosphate levels before and after use.

Judy

[Carl]

Interesting question, as I have not been asked this before other than how phosphates relate to planted aquariums or reef aquariums.

With reef aquariums, in particular those with corals, along with planted aquariums I have always aimed as close to 0 as possible.
I also agree that a small amount of phosphates are needed for the Nitrogen Cycle, but based on some rather healthy nitrogen cycled aquariums, very little is needed, probably no higher than .25 ppm

I have no science based evidence of what "Too High" would be, but based on how nitrates seem to affect fish in very high amounts, I would have to say it too would have to be quite high, maybe 5 ppm or higher, but this is ONLY a guess.

As for liquid phosphate removers, I would be careful as many can work just like water softeners and alter water chemistry in ways that continue to drive out essential mineral Cations

My personal favorite way to remove phosphates, especially in planted or reef aquariums where keeping water chemistry exact is very important is simply by watching the water that goes in and using bio methods of removal such as refugiums, skimmers and especially NPX Bio Plastics

Product Resource:
www.americanaquariumproducts.com/TwoLittleFishies.html

This said I have used products such as API Phosphate remover for many years with good results too
Product Resource:
www.americanaquariumproducts.com/Filstar.html#phoszorb

Carl

[Deleted]

Thanks Carl,

While I didn't have algae that would indicate too high phosphates, I did have a slight "white" haze. I never had that problem once I started using the purchased water. I can really tell the difference in the tap water and the purchased water. The water from the tap looks very cloudy next to the purchased water (buckets placed side by side). My son was actually the first to point out my cloudy water and it was even after a water change.... Sometime from 2010 to 2011 the water treatment plant started using something else to buffer that water, I suspect - a buffer high in phosphates perhaps? Certainly was NOT an alkaline buffer.

I did all sorts of searches to see what all could cause a slight haze in water (when bacteria bloom wasn't the cause) and did find high phosphates could be the issue. The first phosphate removers I used were ferrous oxide -- never again. I had super clear water -- but toxic water. When I used those, I did get phosphate readings as high as 4 ppm (hence the stained plastic test tubes). After I discovered ferrous oxide can turn toxic -- and did when I used one medication -- I got rid of all phosphate removers that contained ferrous oxide.

The Seachem Phos Guard is nice as it can be used in smaller filters in media bags (Like those sold for AquaClear filters). The API particles are too small for the less expensive media bags. I did try to divide one (API) up once - but had to use one of the more tightly woven pouches that Purigen came in (I need all of the Purigen pouches for Purigen -- I just refill those and sew them back up. When I take one out, I let it dry completely -- then dump the product out and, refill and stitch. As written in a different post, I don't recharge my Purigen - actually advice I got from another freshwater fish "expert". He doesn't recharge his for the same reason I don't recharge mine. Cost of all materials needed to recharge isn't much less than the cost of bulk Purigen. What I do saves time, too).

Judy

[devonjohnsgard]

Interesting topic. Last time I checked, mine were around 5 ppm. This was even after using NPX for a short while. It wiped my Nitrates to 0, but phos was higher. I haven't really seen any issues with haze or algae, so I've always kinda wondered when was to high. I wondered if it would control growth rate of plants too.

[angelminx]

Hi, All,

I use the Elos Phosphate test kit (I really need to find a way to get replacement test tubes for it--they are sized and shaped different than API's--because I just broke another one!), which is from Italy, and tests the form of phosphate used most by plants, rather than total phosphate. According to their insert a level of up to 1 mg/l is sufficient for good plant growth--unfortunately the test does not have readings on the color card of over 1 mg/l. However, you can tell if it is over that because the sample turns a darker blue than is shown on the card. I always record +/++ when it reads darker (which my tap water does), but most of the time my results are in the middle or lower range (once it read 0).

Angelminx

[parker002]

Dec 29, 2014 13:54:10 GMT -5 devonjohnsgard said:

Interesting topic. Last time I checked, mine were around 5 ppm. This was even after using NPX for a short while. It wiped my Nitrates to 0, but phos was higher. I haven't really seen any issues with haze or algae, so I've always kinda wondered when was to high. I wondered if it would control growth rate of plants too.

Phosphorous is an essential nutrient for plants. Much like nitrogen, where the delivery method is normally in the form of nitrates, phosphorous is delivered via phosphates. Cutting them to zero would most likely kill your plants. However, with an aquarium, you do have to watch them because unlike terrestrial plants, you have to watch out for algae growth.

[parker002]

Judy,

The cloudiness in your tap water is more than likely precipitated carbonates. Our water around here is super hard and often calcium carbonate (limestone) will show up as cloudy water.

[parker002]

I talked to my local botanist (aka my Dad) and he said nitrogen and phosphorous are equally important.

Nitrogen facilitates leaf growth, which maximizes surface area for photosynthesis.

Phosphorous facilitates root growth, which maximizes surface area for micro and macro-nutrient absorption.

He said if Phosphorous were too low in a fish tank, it might actually AID algae growth, since algae has no roots and could outperform poorly-rooted plants for nutrients.

[Carl]

Jan 22, 2015 12:08:42 GMT -5 parker002 said:

I talked to my local botanist (aka my Dad) and he said nitrogen and phosphorous are equally important.

Nitrogen facilitates leaf growth, which maximizes surface area for photosynthesis.

Phosphorous facilitates root growth, which maximizes surface area for micro and macro-nutrient absorption.

He said if Phosphorous were too low in a fish tank, it might actually AID algae growth, since algae has no roots and could outperform poorly-rooted plants for nutrients.

Excellent points, especially the last point!


This is why phosphates should be low, but NOT non existent.
A similar problem occurs with too much light in the blue spectrum, the algae will utilize this more than the plants. Ditto yellow light and Cyanobacteria

Further Reference:
www.americanaquariumproducts.com/AquariumPlants.html

Carl

[devonjohnsgard]

Thanks for all that Parker.

[parker002]

Maybe this makes me a bad fish keeper, maybe not, but Carl talked me through a period early on in my fish keeping experience where I was spending too much time obsessing about my setups and it was absolutely destroying my enjoyment of the hobby. I was going through what seemed like an endless cycle of losing fish and I was honestly ready to give up the hobby altogether. It took a while (yes, I have OCD ) but I finally got over the hump. I had to learn to leave things alone.

I haven't tested my water in ages. My test strips haven't been opened in months. I vacuum and do water changes maybe every 6 weeks and the only things I really religiously use are Wonder Shells. Other than adding Prime when I add tap water, I don't do anything else regarding water chemistry. Honestly, right now I have no idea what my water parameters are.

That all being said, I have 2 tanks full of healthy fish and plants. My fish mortality has gone down dramatically since I stopped messing with stuff on a daily basis. In fact, I've always taken this hands-off approach with my pond and I haven't lost a pond fish in over 4 years.

Like I said, maybe I'm just not a good fish keeper but I think the real key is to concentrate on the stuff that has the most long-term impact, like getting a UV sterilizer or switching to good LED lighting...

[Carl]

You make some excellent points that I agree with and basically recommend at the core of many of my articles, in particular the "Aquarium Disease Prevention" article. While unfortunately this is not in my top read articles, it more than any other article brings together all other articles and provides points that I have proven in tests and observations as to keeping a healthy aquarium.

My point in this previous statement is for my aquarium maintenance business to be successful meant not only keeping my clients happy, but doing this with as little effort, time, & expense as possible, which in business equals making a reasonable profit (which is sadly lacking in this Internet business). By following these steps which included optimal bio filtration, optimal chemistry, good lighting, UV Sterilization, optimal nutrition, etc., I found that testing and other time consuming expenses were not needed as often.

In fact with many aquariums I found that once I established a baseline for each aquarium and followed it, I could go without testing for some time and then when I did test, the results were EXACTLY what they should be.

Reference:
www.americanaquariumproducts.com/Aquarium_Disease.html

Carl

[devonjohnsgard]

So, if PO4 (phosphate): 1.0-2.0 ppm. is what is required, I'm actually high with a reading of 5ppm. I'll look into methods of removal. Phos-Zorb or I've been thinking about NPX again, because when my Nitrates went to 0, I took it all out. Now the Nitrates are higher again.

Parker, I like your approach as well. For me I do have to add in a bi-weekly or so water check. There is still some movement in parameters. I would check into you GH at least Parker, when I was using wonder shells on a regular bases (new one in when the old on was gone, small chunks) my GH climbed off the charts and last I check was at the limit (500ppm). It's been a couple months and the GH has barley came down.

[parker002]

The standard API or Jungle Test Strips only go to like 500-600ppm GH. Mine is well above that right out of the tap.

[Carl]

Jan 23, 2015 11:22:48 GMT -5 devonjohnsgard said:

So, if PO4 (phosphate): 1.0-2.0 ppm. is what is required, I'm actually high with a reading of 5ppm. I'll look into methods of removal. Phos-Zorb or I've been thinking about NPX again, because when my Nitrates went to 0, I took it all out. Now the Nitrates are higher again.

The Phos-Zorb will do a better job, however SeaChem has a new product out (PhosBond) that combines the phosphate removing capabilities of both aluminum oxide and granular ferric oxide into a singular material forming a synergistic effect.
Since it uses ferric oxide which is the more effective phosphate remover, caution should be exercised in removing the product temporarily when treating with many stronger medications. The positive of this product is that it uses a lower amount than products such as Hagen Clear Max and even if you forget the product is in your aquarium during the use of a strong medication, it should not likely be a problem .
AAP will soon be selling this product too!

Product Resources:
www.americanaquariumproducts.com/Seachem.html#phosbond
www.americanaquariumproducts.com/Filstar.html#phoszorb

Parker, I like your approach as well. For me I do have to add in a bi-weekly or so water check. There is still some movement in parameters. I would check into you GH at least Parker, when I was using wonder shells on a regular bases (new one in when the old on was gone, small chunks) my GH climbed off the charts and last I check was at the limit (500ppm). It's been a couple months and the GH has barley came down.

I would double check with both types of test kits (titration & dip strips), as I have never seen a Wonder Shell bring GH above 500 (unless the tap/well water starts out really high), even at full dose. More importantly, this is exactly the point I believe Parker is making, worrying about GH being too high is one of those knock my head against the wall problems that in 40 years have never seen it be an issue when it comes down to ruling out all other possible issues.

Movement in parameters is quite natural, hence why worrying about these too much just adds to ones blood pressure.
Speaking of blood pressure, according to my Dr., small variations in this are natural too, so using this as an analogy, one should expect variations in water parameters, just not sudden large swings.
Once an aquarium is established, and every procedure is followed exactly the same way, large swings should rarely, if ever happen barring accidents such as a child dumping a whole container of fish food into an aquarium at one time

Carl

[parker002]

So all this talk got me curious. I went and busted out the test strips.

It's been about 4 weeks since my last water change and here are my parameters:

Nitrates: ~20ppm
Nitrites: 0
GH: over 300ppm (test only goes to 300)
KH: ~60ppm
pH: ~6.5

[parker002]

I've never tested the water in my pond. We do 80% water changes once a year.

[Carl]

Jan 23, 2015 12:48:27 GMT -5 parker002 said:

So all this talk got me curious. I went and busted out the test strips.

It's been about 4 weeks since my last water change and here are my parameters:

Nitrates: ~20ppm
Nitrites: 0
GH: over 300ppm (test only goes to 300)
KH: ~60ppm
pH: ~6.5

Your numbers look OK, although I would often keep both pH and KH a little higher, the main idea is stability of pH, which I am guessing you are achieving

Carl

[devonjohnsgard]

I would make the recommendation to hold off on the minerals for a while. If you are testing 500-600 out of the tap, that's actually high to begin with. You could put the shell in and take it out maybe after a hour or so. It's just the electrolytes I would be worried about.