Phosphate -> Likely Culprits

[ncutler]

I'm fairly new into the hobby, as a child I grew up with aquariums, but only now am I really learning the scientific portion.

My tank has just completed cycling (6 weeks old). But I've noticed my phosphate levels are through the roof. At first I thought I was simply overfeeding (which I'm sure I am) but after getting SeaChem's phosguard 4 days ago and no change happening, I think there must be more going on than just overfeeding.

I have been using various chemical products, but the only thing I've lately been using is Nutrafin's Ph Stabilizer/KH Booster. Would this add phosphates to the tank? Another possible culprit - Nutrafin's Liquid Plant Gro Fertilizer. I've also added SeaChem's Flourish Tabs.

There's no algae growth yet (well tiny spot algae and beard algae on one plant that I've removed and bleached), so I'm mostly trying to maintain as near perfect water conditions as I can. It's just frustrating me why phosphate levels have not changed.

I have noticed that my KH is rapidly decreasing - 15 ppm a day or so. This could be connected to the fact that my municipal water doesn't even register any KH, so I've been adding KH using the Nutrifin mentionned above and the plants/nitrifying process is using them up? Could is be phosguard?

Any tips would be greatly appreciated!

 

[three-fingers]

Hi ncutler, I wouldn't worry about the phostphate levels in your water, the idea that phosphate causes algae isnt really held to be true any more, it would have to a combination of factors. Since you don't have much algae there's nothing wrong with your tank, and even if you got loads of algae the best course of action would be to balance lighting levels, fertilisation and review what species of plant you are using in your tank, rather than using chemicals to remove phosphate (which would cause wild swings in phosphate levels, debatabley causing more algae themselves).

To answer your questions though, the phosphate is probably mainly coming from the buffers your using (which, unless you have a specifc reason for doing so, I would also recommend you stop, as swings in KH and pH are generally worse than just dealing with the water stats out of the tap. If you want to increase pH and KH more stably and consistently, the best way to do this is by adding some kind of clcium carbonate based rock to the tank, or crushed coral to the filer.

The flourish tabs will be another source of phosphate (since plants need this), but not in huge amounts compared to the buffers. The Nutrafin Plant grow doesn't contain enough phosphates to make a difference (hence why high-tech planted tank people dont use it).

 

[ncutler]

Thanks three-fingers,

I was starting to conclude exactly what you said. But if I stop using the KH buffers, it will drop to zero pretty quickly. I'm having difficulty understanding the actual important around Carbonate Hardness - especially since tap water here has 0 KH (from the tests at least). Whatever I read in theory seems to make it much more important that it actually seems to be (ph swings, for nitrifying bacteria and for plants).

Should I keep the phosguard running, which might be the cause of my KH reducing so quickly? Stop the buffering? or stop both?

 

[drobbyb]

To balance out your KH issues without using commercial buffers, simply do more water changes. This will normalize your conditions and should prevent a pH crash due to declining KH. Another way to combat this is use of crushed coral as three-fingers stated. It should be said that if you run crushed coral, you are going to have to do more waterchanges anyway. You want to prevent your KH from dropping, not increase it. Crushed coral over time will have a dramatic impact on your KH, and thus you need to perform more waterchanges so that you don't shock your fish on the next waterchange.

 

[rdd1952]

Hi ncutler and welcome to the forum.

As mentioned, don't worry about the KH issue and stay away from the adjusting chemicals. My tap water is the same as yours. GH & KH are both 0 with a pH of about 7.2. The pH in my tanks runs in the mid to low 6s but is stable and the fish I keep prefer slightly acidic water anyway. The only way I would ever consider trying to raise the water stats is if I wanted to keep Africans that need a higher pH and then I'd just go the route of aragonite sand rather than using chemicals.

If you feel you must raise them though, as drooryb mentioned, adding a little (about a teasponful worked on my 29 gallon when I was trying to adjust it) crushed coral to your filter will do it. The water flow will gradually raise the KH and buffer the water more. But it will have to be replaced over time.

But still, your fish and tank will be fine with a KH of 0.

 

[ncutler]

Thanks all for your replies.

Part of the reason I got my aquarium is to learn as much as I can, so I've found it easy to learn the theory, but lack in the practical still. The theory of KH is driving me nuts, because it seems to go against my observations - That having 0 KH won't necessarily cause huge fluctuations in the Ph.

Lots to learn still!

 

[rdd1952]

It does seem to be something that would be an issue but I think the reason it doesn't cause problems is that we aren't adding new things to our tanks. For instance, if your KH is 0 and you drop in a decent size piece of limestone or something like that, the pH (along with KH) will shoot up because you have altered the situation. But once the tank is running, fish and plants are in, from that point on, all we add to the tank is food and maybe ferts for the plants. So no real items to alter pH, GH or KH, thus they stay relatively stable.