Phosphate problems, FW   4/30/07
Dear crew,
<Erik>
I have recently set-up a 30 gallon tank. I'd like to make it a fully planted freshwater show tank. I have kept saltwater tanks for 20 years but haven't done fresh in a long time. The aquarium has been up for a month with no fish because I am trying to get my phosphate levels down below 1.0 ppm. with no luck. The only things in the tank are 10lbs of Carib sand under 60lbs of Eco-Complete and a piece of driftwood that I bought at a fish store and soaked for a week.
<Mmm... this could be the source of the HPO4 here...>
Over the month I have changed 100 percent of the water with no change to phosphate. I have tested my tap water and get a reading of 0 for phosphate. The pH is high and I have been buffering that with Seachem's Acid Buffer which claims to not be based on phosphate. I have run Kent's phosphate sponge through my Whisper 40 with no effect and currently have 2 Whisper 40s both with phosphate remover as a last ditch effort. I don't know where this phosphate is coming from as nothing living has ever been in the tank. I have never had the lights on either so no algae is present. Any insights and help is greatly appreciated.
Thanks,
Erik
<I would try two things here... for now... Removing the driftwood (soaking it in more water, testing it there)... and "checking your checker"... testing your test kit against another (possibly at a fish store). Bob Fenner>

Phosphate + pH, FW...   4/30/07
Hey guys,
I should have asked this straight out when I asked about my phosphate question, sorry about the dual emails. I mentioned I was lowering my pH with Seachem's Acid Buffer. The problem is that my pH constantly raises no matter how many times I add the buffer. I have a Pinpoint monitor and can see it go up slowly but surely every single time. My pH from the tap is high, around 8.0, but I thought the Acid Buffer would lower it and keep it low.
<Mmm... you need to understand the relationship of (the unfortunate term) alkalinity... or buffering capacity... as it relates to pH... You likely have a situation with chemical species that "rebound" the pH... from your source water... perhaps the decor, substrate... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwph,alk.htm
and the linked files above>
But up it goes. Once I add fish and plants I would have to add Acid buffer every single day to keep the pH at 6.8-7.0 as I want it.
<You don't want to do this... Such changes should be made gradually... with water adjusted outside the system... not by pouring in chemicals into the main/display tank...>
If I went away for a weekend it'd be 7.5 or higher in a day or two without it. Not good for tankmates I'm sure. Any help? I truly appreciate what you folks do for us in the hobby.
Erik
<Read on my brother, read on. Bob Fenner>

Science Fair Project
Dear Mr. Fenner,
I am a seventh grade student and I am doing a science fair project for school. The topic I picked to research was the effect phosphates have on green algae growth. I mixed stock solutions of graduated strengths of river water with detergents containing phosphates. I used Cascade detergent and Glass Magic. Glass Magic had more phosphates in it then Cascade. I then added 1ml of green algae to each solution. My hypothesis was that the jars containing river water with the highest concentration of phosphates would grow the most.
All of the research I did prior to my experiment pointed in that direction.
The actual results were different. The highest concentration of phosphate river water turned the algae to white grains and then it all disappeared.
The river water with the next highest concentration of phosphates started to decay and turn brown. This all happened over a three week period of time.
I have been searching for books in the library and also on the internet that might help explain my results. I came across a few articles that you wrote and your question and answer segment that you have. You seem to be very knowledgeable when it comes to algae growth. Can you help me. It appears as if the results of my project defy logic. Can you help explain what might have happened to my algae?
<Don't know if I can. The "Discussion" of results in a scientific study is often the most important, most revealing part of an investigation. What do you think might be factors, co-factors here? Did you "run controls" with no detergent addition? Perhaps there is/was/were other influences in your test model other than the addition of detergents, phosphates... Is there some reason if the study was about soluble (I take it) phosphate that you utilized dishwashing material? The other chemical properties of these products might well account for the changes you observed... perhaps you might repeat the experiments with just the equivalent concentration of HPO4... Maybe other conditions of light, heat, water chemistry might be tried to see if they'd render the same results, perhaps lower concentrations of the test chemicals would prove less toxic.>
I would like to thank you in advance for your time regarding my letter and possible answer to my question. Have a great weekend.                                                                 Thanks,                                                                        Mario
<Do consider having a reference librarian show you how to do a computer search bibliography. Please see here re: http://www.wetwebmedia.com/litsrchart.htm
Thank you for writing. Bob Fenner>