phosphate

[cbster]

what is the best way to remove phosphate from the tank?i just tested my tap water and it hit very high on the charts no wonder i have algae growing like crazy. thanks Greg

[SnakeIce]

get your plants to grow like crazy:D
as to how to do that maybe some of the other members would be better at that than I

[Starry]

How high exactly? Unless it's over 1.5ppm, I'd leave it alone. I've dosed to 1.25ppm without any problems, and lots of people have been known to go above that. It's not necessarily the source of your algae problems. How are your plants? They may be lacking potassium or traces. If your plant growth isn't good, start dosing potassium and traces right away, and the plants will happily use up the phosphates. I'm assuming here that you have a decent amount of light and hopefully CO2. Otherwise you're right, too much phosphates won't be good if the plants can't use them up. I'm also hoping you have lots of plants. It's hard to have a successful planted tank with few plants.

[cbster]

the phosphate level was higher than the chart would read. the highest was 4.0. but that was just in my tap water but i haven't used anything to get it down in my tank. i have been putting flourish and i put in flourish tabs in the gravel/laterite. i have 160 watts of light on a 55 gal tank. and i am using a diy co2 system the last reading was 18 ppm on co2. i just planted 46 varies plants in the tank on 12-24 so they are new plants that are small. haven't seen much growth yet. thanks alot Greg

[Starry]

Wow, that high? I'd try leaving it alone for now, just because it would be a pain trying to remove it at every water change. Hopefully someone can give you better advice than that.

test your tank water though. Maybe you made a mistake.

You're doing good with light, CO2 and traces. Start adding potassium and see how it goes. The beginning is always tough. Your plants will take a while to get settled, so you won't see massive growth right away, and some plants may die back.

[DIYMatt]

IME- everything with aquatic plants is about balance. Having one nutreint high is only a problem if you are lacking others. Have you tested your Nitrates? You will need some Nitrate to get your plants to grow and use up the Phosphate. Test for Nitrates and if they are under 5 ppm, you should dose with KNO3 to 5-10ppm. More info on that if you need it, I suspect you won't though. Also, water changes are huge, I do 40-50% a week. I would go any less than 30% a week, and thats only if you are careful with your dosing.

But, with your fertilization regime you are probably still lacking Potassium which is a huge factor in plant growth. You can either buy Flourish Potassium and dose with that, its good, but very expensive. I use Nu-salt salt substitute from the grocery store's spice aisle. It is Potassium Chloride in a dry form. . I would start with 1/2 tsp dose and then 1/4-1/2tsp twice a week. I mix mine with water first, or dump it dry into a HOB filter if I have it on that tank. It doesn't dissolve all that fast for me. I use this calculator to guage all of my fertilization levels. I usually start dosing enough to reach the target levels in a week. Here:http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

About your Phosphate test; have you verified these results by taking a water sample to a LFS and check to see if your test kit is accurate? Some of the Phosphate tests can be inaccurate. If your Phosphate is that high, it could be throwing off your CO2 level if your are using the CO2/KH chart method. There was a discussion on another board about how having phosphate buffers can cause you to have inaccurate CO2 readings by the chart method. Also, call your water department and ask them for a water analysis and find out what they are putting in the water. I have never personally heard of a Phosphate reading of over 4 from the tap.

As far as removing the phosphate, all of the methods I know of mess with other nutreints your plants need also. I don't suggest any of them. So, lets try to get your plants to use them first, before you try to remove it, they need some after all to grow. The algae your expereincing is unfortunately common in a new tank, unless you take steps to prevent from the outset of the tank. Usually after the tank cycles/balances a lot of the algae problems disappear.

Also, more info about your tank would be very helpful/necessary. Like all of the following: Ph of tap water that has sat out over night, Ph of tank water with CO2, KH, GH, Nitrates, Ammonia(if any), temp of the tank.

[Tim Bo]

Yes DIYMatt, some good points you bring up, especially about phosphate 'buffering' and CO2 readings (I realize this is a little out of context, but an important consideration to be aware of when using the chart. In typical soft freshwater (no phosphates or other salts), bicarbonate is the predominate buffer and KH = alkalinity and the table can be used to determine CO2 from pH and KH. High phosphate levels can screw things up a little when using the chart, especially in terms of carbonate hardness. If you have high phosphates or other buffers present, the "KH" test kit will read high and the table will give you incorrect values for CO2 based on pH and KH. However, if you have a CO2 test kit, you CAN determine the true carbonate hardness by measuring pH and CO2 and getting KH from the table.

[cbster]

Thanks alot for all this info i will post all the info on the tank tommorow i just did about a 25% water change and i will test everything tommorrow night. i was just headed to the store to get some nu salt to add to the tank. thanks alot Greg

[DIYMatt]

Tim- thanks for clarifying. I forget about actually testing for CO2. Sorry!

[cbster]

alright here is my tank info. ph of tap water set overnight is 7.0, ph of tank water 7.2, kh 6, which by using the chart is suppose to be a co2 of 11, which i am at the end of my co2 mixture. gh 4, ammonia 0, nitrite 0, nitrate 0, and the temp of the tank is 77 degrees. Thanks Alot Greg

[plantbrain]

Ask the tapm water supplier for a PO4 reading and also ask if they add it.

I do not believe they need to add PO4 where you are at(water is not particularly soft).

My bet is partly the test kit.
Regular routine water changes should lowwer to .5ppm or less(it's unlikely the tap has more than that which should be lapped up by plants fairly quick if you enough CO2/NO3 in the tank))

So just do some 50% weekly water changes.

Regards,
Tom Barr