[macuserman]

First a little background and then my question. I have been having trouble keeping the nitrates down in my tanks. Part of the problem is that my tap water that I use for water changes has high nitrates. So if I do a water change the best result I can ever hope for would be the same level as my tap water which I will never achieve unless I did 100% water changes which are bad and I'm not going to do that. My tanks are all heavily planted, I use CO2, medium to high lighting, Eco-Complete substrate, and dose weekly with flourish excel, and flourish iron.


The plants are growing like crazy and my fish seem to be happy as well for the most part. There are some more sensitive fish I'd like to get and so I picked up an RO unit in a bulk buy of some used aquarium stuff I bought.

I've got the RO unit installed, I've replaced all of the filters and I've got nice 4ppm TDS water coming out into my holding container. Now my understanding is that I need to add back some of the minerals to the water for the best results and to that end I've purchased a bottle of Seachem Equilibrium.

So now I've got a great big tank of nice clean RO water and I'm not sure where to go from here. My question is how do I know how much equilibrium to add back so that my plants don't go into shock and die as well as my fish? I bought a KH GH API test kit, but I'm not sure what I should take into consideration for what my target levels should be.

Any advice on this would be much appreciated.

Thanks!

 

[Pattern8]

Can you list the species you currently have and about how long you've had them? Also the GH and KH of the tap water you had been using up till now? Lastly, what species were you hoping to introduce to the tank?

 

[macuserman]

Can you list the species you currently have and about how long you've had them? Also the GH and KH of the tap water you had been using up till now? Lastly, what species were you hoping to introduce to the tank?

I have a couple of tanks so these aren't all in the same tank:
Bolivian Rams -4 months
Angel Fish - 1.5 Years
Bushy Nose Albino Pleco - 6 months
Clown Pleco - 1 week
Bumble Bee Catfish - 4 months
Scarlet Badis - 3 months
Otocinclus - 8 months
I moved last august to a GA from TN and my angelfish were really the only thing that survived the move. My rams all died and my attempts to replace them have been futile.

The test kit won't arrive till tomorrow from Amazon so I'll post those results when I get it. I couldn't find a local store with that particular test.

The species I'm wanting to add are GBR, I had a couple of really nice breeding pairs at my old residence where the nitrates in the tap water were very low. But all my attempts to keep them currently result in dead fish very quickly. So I'm starting with my water parameters and going from there.

 

[Pattern8]

In full disclosure, aside from the oto, I've never personally kept any of those species
According to various fish profiles though the hardness is listed as follows (all in °dGH)
Bolivian Rams: 1-10
Angel: 0-5
Plecos: 2-12
Bumblebee catfish: 3-8
Scarlet badis: 1-15
Oto: 2-10

In my mixed species tanks I've tended to reconstitute my RODI water to the minimum required. For example if one species was listed as 0-4 and another as 2-15 I've aimed for 3°.

All of the fish I have were wild caught and so probably classified as more sensitive. I did experience some pretty wild GH swings during the learning curve with RODI water but luckily with no loses. However, many people on this forum with much much more experience than I strongly advise a very gradual change in GH. Some have said a large swing in GH can be more disastrous than ph swings.
So it's probably best to test the GH in your tap water and start there- slowly bringing your GH to the level desired in 1°-2° increments with each water change.

As to determine the amount of equilibrium needed Seachem has both a mobile app as well as a feature on their website that will allow you to plug in your water volume as well as current and desired level. It will then calculate the amount of product to add.
On a side note it currently only allows you to enter current and desired level in meq/l. I find it easier to work with °dh since that is the measurement used in the api test. To convert you simply divide your desired dKH number by 2.8. Ex: 3° dKH = 1.07 meq/l

My personal experience is that their recommended amount (and I measure out down to the milligram) will produce something just slightly under what is expected. Either that or the api test is just not capable of such a precise measurement. Either way it has not been great enough to cause concern.
The other issue is that it can be difficult to dissolve, especially as the product ages in the bottle. I usually make my replacement water about a week in advance which allows it plenty of time to dissolve. Others here have recommended a similar product by Green Leaf Aquariums and have found it dissolves much more easily but I have no experience with it.

One last thing about using RO water that I have found very helpful is that once you have got your levels locked in you can test the TDS of your replacement water and use this as a kind of base to determine when water changes are due.

 

[macuserman]

Ah ok this makes a lot of sense. I've only got a 15gallon holding tank atm so it sounds like I need to upgrade that tank size so that I can have a little more water on hand since I tend to do my tank maintenance all on the same day esp if I want to let it sit for awhile before using it. This was very helpful information, based on what you've said and my own research sounds like a target of 4 would be appropriate. One thing I didn't hear you mention was plants, are they less important to consider than the fish?

 

[Pattern8]

In my experience no, I had no known effect on plants. I believe as a general rule aquatic plants prefer soft water with a GH in the 3-6 range.
As I mentioned before I had one tank with crazy swings in GH. It was actually this tank that led me to purchase a RODI unit in effort to control GH. Its a 6 gallon nano tank that I hardscape heavily with seriyu stone. My GH was going from anywhere between 3 to 20 from week to week lol! I have several species of flora that have been in the tank the whole time. Many of which I read were very sensitive and would only grow in low GH and acidic water. I have finally gotten the parameters pretty steady with a GH of around 7 or 8 and a ph of about 7.4-7.6. Every single one of the plants have done well and I have to trim this tank more than any of my others.