Water Levels Have Gone Haywire.

[sparklefuzz]

I replaced the gravel in my tank with sand about 4 weeks ago and now all the levels have gone haywire.

The ammonia and nitrites are fine.

Nitrates - 100 !! - I put a nitrate removal sponge in my juwel filter, 3 days ago. It was at approx 150.
GH - dropped from >10 to >6 in the last few days
KH - about 2, was at about 3-4.
PH dropped to about 6.5 ish. It is usually about 6.8, which is still low... but the fish been ok.

I bought some tetra 'easy balance' yesterday and dosed the tank, the nitrates have fallen since, to 100 and the KH has increased slightly, only by about 1 though.

I did a 30% water change on saturday before adding the nitrate sponge, but it hardly affected the nitrate levels.

I'm worried because the GH, KH and PH seemed to have dropped in the last week or so, they were fine immediately after the substrate change.

Bit of info, I have a 180l tank which was given to me a year ago by my father, who is now in India, so not available for help! I've performed weekly water tests, and weekly 25% water changes since day one and the levels have always been acceptable. Like I said, the PH was always on the low side. The nitrates have always been around the 50 mark. The day I changed the substrate we also rehomed 4 huge blood parrots.

I'm not sure what to do, can someone please give me some advice?

 

[BiffMalawi]

I have never used sand but I think daily lartge(30%- 40%) water changes are in order until the nitrates drop to 10. If your ammonia and nitrites are 0, then at least everything is working well. I am concerned where all the nitrattes are coming from.

When you say rehomed four huge blood parrots, did you put them in or take them out?

What fish do you have in there?

How much and what food are you feeding?

Is it possible you have some dead fish, snails, plants in there?

I think what you are after is what is creating a lot of ammonia(like the above) as it is what eventually becomes nitrates. Your water change schedule sounds perfect, but 50 is too high for a regular reading, my tanks never hit more than 20 and my water change schedule is the same as yours.

It really sounds like overfeeding. It took me years to get used to how little to feed as the fish always seem hungry.

 

[sparklefuzz]

When you say rehomed four huge blood parrots, did you put them in or take them out?

We took them out.

What fish do you have in there?

4 corys, a gourami, a pleco and 4 small angelfish.

How much and what food are you feeding?

Tetra Pro, every day, small amounts.

Is it possible you have some dead fish, snails, plants in there?

No, definately not. Although I've just taken out one of the corys as he is dying.. or so it seems. I've posted in the emergency section.

I'll ease up on the feeding. We used to feed every other day, but since we got the angelfish we feed everyday because they're only babies. Would every other be ok? I'll start doing smaller water changes daily and see how I go.

Thank you.