Tropical Fish Forums

[urchinblue]

hello
I work in a petstore in the southeastern virginia area, which has been known to have high phosphates present in our tap water.
Both our fresh and saltwater tanks have very high phosphates; both are maintained using D.I. water, buffered with seachem's "marine buffer" or neutral regulator", and are consistently maintained, the saltwater tanks are waterchanged once a week, and we're still getting phosphate readings upwards to 5.0, freshwater tanks are waterchanged about once every two to 3 weeks, and are reading off the charts (^10ppm);
they are not being overfed, and the buffers are not being overdosed. The D.I. unit is operating as it should, so far as I know, and is up to date on any maintainance and replacement of parts, and water exiting the system contains only trace amount of phosphate when tested.

I guess my question is, what's going on? I'm at a loss to explain this. Is it possible for phosphate to be binded with something else that is getting through our D.I. filtration unit, and then is released later on? That's the only thing I could think of.

thanks for your help,
confused.

[fishlover888]

I know some of the buffers are phosphates based. You may want to check that to make sure.
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125 g discus tank 13 discus, 5 Sterbai cory, 3 clown loaches, 1 Albino BN pH 6.3 50% WC x2/wk
2 g nano tank 3 Danio, pH 7.6 80% WC/ 2 days

[unissuh]

What sort of filtration methods are we talking about in the saltwater tanks?

fishlover888 is correct for the freshwater - SeaChem's Neutral Buffer is a phosphate based buffer. I can't see this being dosed into a saltwater setup though...

http://www.seachem.com/support/FAQs/NeutralRegulator_faq.html

I am curious as to why you dose neutral buffer into your fishtanks, is it because you are getting pH swings? In a LPS, this is usually because of the high density in sale tanks...most LFS/LPS here get around this by changing the water a lot more frequently than once every 2-3 weeks through a flushing system (we're talking just about every or every other day).

Do you know what sort of nitrate reading you are getting? I'm guessing that although you are not overfeeding relative to the amount of fish that are in the tanks, there are too many fish in there for the tank/water change regime to handle. I suspect that in addition to your high phosphate, you have high nitrate.
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Fishing in the Rivers of Light

[urchinblue]

the saltwater systems operate on wetdry systems, with a mechanical prefilter that is rinsed out every week, completely replaced every other week, and incredibly efficient skimmers that pull a lot of gunk out of the water.
The freshwater systems run on a sort of huge sponge filter.
Though this hasn't been done in the past, we are slowly introducing live plants to both; in the SW tanks we're planning on using some of the room in the sumps to grow caulerpa (sp?), in hopes of making the tanks healthier overall.

actually, our nitrate readings on both the fW and SW systems are between 0-5ppm. This is what's so baffling about it, because I assumed the same, that had it been due to overfeeding/overstocking, high nitrates would accompany this. We test nitrates once a week in FW, twice a week in SW, and have recently used 3 differant brands just to make sure we were getting correct readings

no, we don't dose neutral regulator in SW; I suspect that in the freshwater tanks, part of the problem may be that in the past, the buffer was seriously overdosed, and may have worked it's way into those sponges where it slowly leaches out. We use the buffer because we use D.I. water for our waterchanges (due to the crappy quality of the tap), and it's extremely soft and acidic.

since I've posted this, we've started going through and, one by one, completely draining and refilling the tanks. The fish are doing OK with it (we bag them up and set them aside for a few hours while the water warms back up)...we're going to monitor the phosphates on a few random tanks from there, and figure out the rate at which they are increasing.

I guess my only other question is besides being introduced by phosphate buffers, are there any other ways that phosphates can be really high in a tank with absolutely no trace of nitrate, and does that indicate some other problem?
I was thinking along the lines of dirty pipes, environmental contamination...I don't know about those things though.

[unissuh]

Honestly, no idea.

To my knowledge, phosphate doesn't tend to be absorbed into equipment or other surfaces to be released later. I'll admit I'm not 100% on this though. Don't really think it's environmental contamination either.

Perhaps check that the type of food you're feeding is not excessively high in phosphate, and make sure that the test kit is reading the right levels.
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Fishing in the Rivers of Light

[urchinblue]

yeah, I'm kinda at a loss too.
I guess we're just going to try to get them all knocked down the only way we know how (massive waterchanges), and go from there. Hopefully the plants in the tanks will prevent this from reoccuring in the future.
thanks for all your help, and I'll check back periodically to see if anyone has any ideas.
-urchinblue