Tap Water And Three Tanks Different Parameters...why?

[cowgirluntamed]

Ok...I have a 5 gallon, 10 gallon, and a 20 gallon tank. All test different from each other as well as the tap water(mostly the kh and gh). I just don't know why this is? Here are the results and some details for each tank. Most water changes were 25% sometimes 50% when I did them...trying to get better!

First off...tap water. It is well water and not from a municipal water supply. No chlorine or chloramines.

pH- 8.2
Ammonia- 0.25
Nitrite- 0
Nitrate- 5
KH- 15
GH- 17


5 gallon tank. Houses one betta, three nerite snails, and now 2 or 3 ghost shrimp added 2 days ago(well...5 were added, 2 were dead next morning. 1 is MIA maybe) Sand substrate with crypt wendtii brown, corkscrew val, dwarf sag, and algae(hair algae and some darker green stuff now...). Crypts and algae growing great. Others are hanging in there. Warrior helmet bought from petsmart as decor. Temp is 80-81f. Finnex stingray light on for two 4 hour shifts I think...trying to do that for the algae. I put in 5 flourish root tabs...so that could be my main problem with what I think now of is too strong of a light. Filter is a SunSun HW-603B 106 GPH 3-Stage External Canister Filter with the sponges that came with it. Nothing else added. This tank also is the one that is the MOST different! Oh and not many water changes. Maybe once a month since setup on December 14th, 2015. Last one was last week though. I'm trying to do better! I also used Dr Tim's One and Only as well at setup.

ph- 7.4-7.6 (I did the high and low pH test. It seemed pretty close to 7.6).
Ammonia- 0-0.25
Nitrite- 0
Nitrate- 5
KH- 6
GH- 13


10 gallon tank. Now holds three guppies and 2 nerite snails. Running just over a year I think. Started with 7 guppies and plants that didn't make it. Only have three different types of anubias in there plus 2 medium pieces of Malaysian driftwood and plastic plants. Gravel substrate. Aquaclear 20 filter with 2 sponges and Aquaclear biomax. Temp is 77f. Treated with two courses of API tetracycline a few weeks ago. Left carbon in for a week and a half and took it out last week while i did a water change. Guppies still don't look great but not sure what else I can do. I did start to use Prime in this tank too. Maybe a bit too many drops as I'm not sure how much to put in the smaller tanks. Bigger airstone added right before the treatment too to help with water movement. Just a regular marineland LED light that has moonlights. Have it on a timer for 12 hours.

pH- 8.2
Ammonia- 0-0.25
Nitrite- 0
Nitrate- 5-10
KH- 9
GH- 11


20 gallon tank. Houses 7 black neon tetras, 3 glowlight tetras, 1 almost four inch female bristlenose pleco. Tank going for 2 years. Sand substrate. 2 different anubias plants. 2 small/medium pieces of Malaysian driftwood and 1 small piece of mopani driftwood. Plastic plants. Medium castle decor. Long airstone. New SunSun HW-402B 3-STAGE AQUARIUM CANISTER FILTER + 9W UV STERILIZER 265 GPH FRESH/SALT 75 Gallon. Media is fluval prefilter media, a course, then medium, then fine sponge. Polyfil quilt batting. Then 1 1/2 boxes of fluval biomax. This filter was added a month ago but I haven't seen much change in test results. I also used Dr Tim's One and Only in the tank when I set the filter up because I took the sponge filter out to redo the decor a bit. Temp is 77f. Water change was last week. Added 20 drops of prime to the tank after to see if that would make any difference in results and I don't think it did really. New fluval aquasky light with the fluval timer. They love the ramping! 12 hour setting.

pH- 8.2
Ammonia- 0-0.25
Nitrite- 0
Nitrate- 10
KH- 13
GH- 15



Anyway....any clue why as to these results 20 would be different? I figured between the 10 and 20 that it might have been the medication? But the 5 is totally different....do I need to be more careful doing water changes and maybe not even do 25% with that one? I don't want to shock my betta or anything. And especially now that I added those shrimp(if he lets them survive). If there is anything else I may have forgotten to add..please ask! I'm just curious if anybody has any idea or experienced this at all themselves.

 

[StevenF]

The likely cause is a mineral imbalance.  Excess phosphates or potassium can cause this.  It is also possible for other elements calcium, magnesium, and sodium) to cause this.  I have seen this with excess phosphates,  The exact parameter changes will depend on the exact mineral composition of the water and will likely be different between tanks.  Also if you have plants the plants will probably pull mineral out of the water (especially with rapid growth) and that could also affect PH, GH, KH.   My guess is that you are not replacing enough water during each water change to maintain stable parameters.  I would recommend a 50% water change once per week.

 

[cowgirluntamed]

The tanks themselves seem stable each time I test though. The 10 and 20 may be a tad different sometimes but the 5 tested the exact same last week. I don't know if it's a good idea to do a 50% change in the 5 because of how different it is. Wouldn't the difference possibly shock the fish? The 10 and 20 are close enough they don't worry me as much. (Details about what each tank has in it are in the first post.)

 

[Flubberlump]

When you say dark green algae, what does it look like? I could be Cyanobacteria which isn't actually an algae. I have a bit at the moment growing on some moss that's growing right at the top of the tank. I had some on top of some floating plant once a few years ago too. I don't know whether it's characteristic of cyano to grow at the water surface or not. It looks like dark green slime.

 

[cowgirluntamed]

It almost seems a bit hairy looking but not like the strands of hair algae that killed the floating plants in the tank. That seems a bit more under control. But this dark green stuff starts at the bottom on the sand and grows up the glass of the tank. I tried to get it off the sand but it just clumps to it so I end up taking sand too. I don't believe it's on the plants though. Just seems to like the sand and the glass.