low Kh & pH

[BarbaraM]

Hi. I'm very new at this. I inherited a very dirty 25 gal aquarium from a family member. It is about 4 yrs old. I have an 8" plecostemus(sp) a 3" clown loach, and two silver dollars. They all made the move from her house to mine. I've had the tank a wee. The chemistry was nasty. I've been doing 50% water changes every other day with R/O water. I'm using test strips to test my water. There are no nitrites - that's good. I've gotten my nitrates from off the chart to between 40-50 ppm. I figure one more water change will get it down to the safe level. The readings for GH were off the chart to begin with, but they are down to about 150ppm. But the Kh and pH are not changing - they are staying on the bottom of the chart. KH at 0 and pH at 6.2. My fish seem to be doing ok? They had been living in the nasty water for quite some time. Any advice?
Thanks, Nana Barbara

 

[melosu58]

Barbara I`m going to move this where you`ll get more help. In the mean time post again on this forum and tell us about yourself. Alot of folks wont see this post unless I move it to the appropiate forum. I`ll start by telling you welcome to AA.

 

[Purrbox]

The reason that your KH and pH are off the bottom of the charts is that you've been using RO water for your water changes. You need to either use tap water treated with a good dechlorinator like Prime, or reconstitue the RO water with buffers etc. Unless your tap water is so nasty that you wouldn't even consider drinking it, then I'd recommend sticking to the tap water since it will make water changes much easier.

Unfortunately most of the fish that you inherited will get much too large (may already be too large) for such a small aquarium. You'll either want to take them to an LFS to exchange for fish that are an appropriate size for the aquarium or upgrade the aquarium to one big enough for the fish.

Welcome to the forum, Nana!

 

[An t-iasg]

Welcome to AA!

Is there any specific reason you're using RO water for water changes? That is probably why your KH and pH are low. The KH and pH values that you're reporting are close to what I have measured in RO water. If your tap water is safe to drink, you can use it for your aquarium. I would do water changes with tap water and the RO water mixed to let the fish gradually get used to the change. At every water change, gradually increase the tap water and decrease the RO water.

Test strips can be inaccurate. Use a liquid-based test kit like this one: Aquarium Water Testing: Aquarium Pharmaceuticals Freshwater Master Test Kit

Those tests are also sold individually. They will give you a better idea of what is going on than the strips, and they are easy to use.

Since you say the fish were living in nasty water for some time, I am thinking that they are used to high nitrate levels. Ammonia and nitrite are different stories - you must do frequent water changes to bring those levels down if they are high. But fish accustomed to high nitrates will have a hard time tolerating a suddenly-lowered level. Change smaller quantities of water (10%, maybe twice a week, instead of 50% every other day) and only if your ammonia and nitrite values are 0 as verified by a liquid test kit.

In the long run, these fish will end up outgrowing this 25-gallon tank. The tank is not big enough for any of these fish at their full-grown size.

 

[BarbaraM]

Thanks guys. I'm using R/O because I don't drink the local water - very hard - leaves white gunk (lime?) on faucets, etc. Tastes nasty. Thought the R/O water would be better. I don't have room for a larger tank, so I guess I'll have to think about trading them in - but I'm already growing attached. I'll try mixing some tap water (treated). I just tested it with my strips (I know, I'll look tomorrow for some better testing equipment) and it tested very high in KH & pH. Maybe I could mix them a little. Thanks for all the advice.
Nana Barbara

 

[Purrbox]

How high is Very High? Actual numbers are much more helpful since what the kit labels safe, low, high etc may the actual cause of a problem or perfectly fine despite with the kit indicates.

Mixing tap water and RO water is one of the better ways to soften tap water that is overly hard. By using some tap water it will replace the buffers and minerals that are needed in an aquarium. This is one option if you decide against using pure tap water.

 

[BarbaraM]

How big are my fish supposed to get? There seems to be SO much empty space in the tank, it seems strange that it could be too much soon.
Barbara

 

[Purrbox]

Pleco easily upto 2 foot
Clown Loach upto 1 foot
Silver Dollars upto 6 inches

 

[BarbaraM]

holy cow!